diff --git a/.github/workflows/reviewdog.yml b/.github/workflows/reviewdog.yml
new file mode 100644
index 0000000..002dc8e
--- /dev/null
+++ b/.github/workflows/reviewdog.yml
@@ -0,0 +1,27 @@
+name: reviewdog on Pull Request
+on: [pull_request]
+jobs:
+  golangci-lint:
+    name: runner / golangci-lint
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out code into the Go module directory
+        uses: actions/checkout@v1
+      - name: golangci-lint
+        uses: reviewdog/action-golangci-lint@v1
+        with:
+          github_token: ${{ secrets.github_token }}
+          golangci_lint_flags: "--enable-all --exclude-use-default=false"
+          reporter: github-check
+
+  misspell:
+    name: runner / misspell
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out code.
+        uses: actions/checkout@v1
+      - name: misspell
+        uses: reviewdog/action-misspell@v1
+        with:
+          github_token: ${{ secrets.github_token }}
+          reporter: github-check
diff --git a/.gitignore b/.gitignore
index 21036cc..910fc80 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,6 +1,9 @@
 .envrc
 .vscode
+.bin
+*.zip
 node_modules
+apache-livy-0.7.0-incubating-bin
 
 jars/target
 jars/project/target
diff --git a/.golangci.yml b/.golangci.yml
new file mode 100644
index 0000000..22efde4
--- /dev/null
+++ b/.golangci.yml
@@ -0,0 +1,63 @@
+linters-settings:
+  golint:
+    # minimal confidence for issues, default is 0.8
+    min-confidence: 1.1
+
+  lll:
+    line-length: 180
+
+  funlen:
+    lines: 200
+    statements: 130
+  dupl:
+    threshold: 150
+  gocognit:
+    min-complexity: 40
+  errcheck:
+    # report about not checking of errors in type assertions: `a := b.(MyStruct)`;
+    # default is false: such cases aren't reported by default.
+    check-type-assertions: false
+
+    # report about assignment of errors to blank identifier: `num, _ := strconv.Atoi(numStr)`;
+    # default is false: such cases aren't reported by default.
+    check-blank: false
+
+    # [deprecated] comma-separated list of pairs of the form pkg:regex
+    # the regex is used to ignore names within pkg. (default "fmt:.*").
+    # see https://github.com/kisielk/errcheck#the-deprecated-method for details
+    ignore: "fmt:.*,os:.*,Close"
+
+linters:
+  disable:
+    - dupl
+    - maligned
+    - gochecknoglobals
+    - gomnd
+    - wsl
+    - godox
+    - gocyclo
+    - interfacer
+    - unconvert
+
+issues:
+  exclude-rules:
+    - path: _test\.go
+      linters:
+        - ineffassign
+        - gocyclo
+        - errcheck
+        - dupl
+        - gosec
+  # List of regexps of issue texts to exclude, empty list by default.
+  # But independently from this option we use default exclude patterns,
+  # it can be disabled by `exclude-use-default: false`. To list all
+  # excluded by default patterns execute `golangci-lint run --help`
+  exclude:
+      - should have comment or be unexported
+      - S1000
+      - ST1000
+      - ST1003
+      - ST1020
+      - ST1021
+      - G304
+      - G402
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..dc7a5d7
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,10 @@
+
+livy.install:
+	wget -q -O tmp.zip http://ftp.kddilabs.jp/infosystems/apache/incubator/livy/0.7.0-incubating/apache-livy-0.7.0-incubating-bin.zip && unzip tmp.zip && rm -f tmp.zip
+
+livy.start:
+	apache-livy-0.7.0-incubating-bin/bin/livy-server start
+
+livy.stop:
+	apache-livy-0.7.0-incubating-bin/bin/livy-server stop
+
diff --git a/README.md b/README.md
index 617c0c9..51e4446 100644
--- a/README.md
+++ b/README.md
@@ -1 +1,20 @@
 # livy-go
+
+## Getting Started
+
+### Livy Setup
+
+1. livy install
+```
+make livy.install
+```
+
+2. livy start
+```
+make livy.start
+```
+
+3. livy stop
+```
+make livy.stop
+```
diff --git a/batch.go b/batch.go
index 192329f..b8267f2 100644
--- a/batch.go
+++ b/batch.go
@@ -4,8 +4,6 @@ import (
 	"fmt"
 	"io"
 	"net/http"
-
-	"github.com/3-shake/livy-go/gensupport"
 )
 
 type BatchesService struct {
@@ -47,7 +45,7 @@ func (c *BatchesListCall) Do() (*Batches, error) {
 	}
 
 	batches := &Batches{}
-	err = gensupport.DecodeResponse(batches, res)
+	err = DecodeResponse(batches, res)
 	if err != nil {
 		return nil, err
 	}
@@ -62,7 +60,7 @@ func (c *BatchesListCall) doRequest() (*http.Response, error) {
 		return nil, err
 	}
 
-	return gensupport.SendRequest(c.s.client, req)
+	return SendRequest(c.s.client, req)
 }
 
 type BatchesGetCall struct {
@@ -84,7 +82,7 @@ func (c *BatchesGetCall) Do() (*Batch, error) {
 	}
 
 	batch := &Batch{}
-	err = gensupport.DecodeResponse(batch, res)
+	err = DecodeResponse(batch, res)
 	if err != nil {
 		return nil, err
 	}
@@ -99,7 +97,7 @@ func (c *BatchesGetCall) doRequest() (*http.Response, error) {
 		return nil, err
 	}
 
-	return gensupport.SendRequest(c.s.client, req)
+	return SendRequest(c.s.client, req)
 }
 
 type BatchState struct {
@@ -126,7 +124,7 @@ func (c *BatchesStateCall) Do() (*BatchState, error) {
 	}
 
 	state := &BatchState{}
-	err = gensupport.DecodeResponse(state, res)
+	err = DecodeResponse(state, res)
 	if err != nil {
 		return nil, err
 	}
@@ -141,7 +139,7 @@ func (c *BatchesStateCall) doRequest() (*http.Response, error) {
 		return nil, err
 	}
 
-	return gensupport.SendRequest(c.s.client, req)
+	return SendRequest(c.s.client, req)
 }
 
 type BatchesDeleteCall struct {
@@ -176,7 +174,7 @@ func (c *BatchesDeleteCall) doRequest() (*http.Response, error) {
 		return nil, err
 	}
 
-	return gensupport.SendRequest(c.s.client, req)
+	return SendRequest(c.s.client, req)
 }
 
 type BatchLogResponse struct {
@@ -208,7 +206,7 @@ func (c *BatchesLogCall) Do() (*BatchLogResponse, error) {
 
 	batchLog := &BatchLogResponse{}
 
-	err = gensupport.DecodeResponse(batchLog, res)
+	err = DecodeResponse(batchLog, res)
 	if err != nil {
 		return nil, err
 	}
@@ -225,5 +223,5 @@ func (c *BatchesLogCall) doRequest() (*http.Response, error) {
 		return nil, err
 	}
 
-	return gensupport.SendRequest(c.s.client, req)
+	return SendRequest(c.s.client, req)
 }
diff --git a/examples/spark.go b/examples/spark.go
deleted file mode 100644
index 718bae4..0000000
--- a/examples/spark.go
+++ /dev/null
@@ -1,151 +0,0 @@
-package main
-
-import (
-	"context"
-	"fmt"
-	"os/exec"
-	"strings"
-	"time"
-
-	"github.com/k0kubun/pp"
-	"github.com/lithammer/dedent"
-	"github.com/3-shake/livy-go"
-)
-
-func SessionsList() {
-	svc := livy.NewService(context.Background())
-	res, err := svc.Sessions.List().Do()
-	pp.Println(res, err)
-}
-
-func SessionsGet(sessionID int) *livy.Session {
-	svc := livy.NewService(context.Background())
-	res, err := svc.Sessions.Get(sessionID).Do()
-	pp.Println(res, err)
-	return res
-}
-
-func SessionsInsert(localJarPath string) *livy.Session {
-	svc := livy.NewService(context.Background())
-	res, _ := svc.Sessions.Insert(&livy.InsertSessionRequest{
-		Kind: livy.SessionKind_Spark,
-		Jars: []string{
-			fmt.Sprintf("local://%v", localJarPath),
-		},
-		Conf: map[string]string{
-			"spark.driver.extraClassPath": localJarPath,
-		},
-	}).Do()
-
-	pp.Println(localJarPath, res)
-	return res
-}
-
-func SessionsDelete(sessionID int) {
-	svc := livy.NewService(context.Background())
-	err := svc.Sessions.Delete(sessionID).Do()
-	pp.Println(err)
-}
-
-func SessionsState(sessionID int) {
-	svc := livy.NewService(context.Background())
-	res, err := svc.Sessions.State(sessionID).Do()
-	pp.Println(res, err)
-}
-
-func SessionsLog(sessionID int) {
-	svc := livy.NewService(context.Background())
-	res, err := svc.Sessions.Log(sessionID).Do()
-	pp.Println(res, err)
-}
-
-func StatementsList(sessionID int) {
-	svc := livy.NewService(context.Background())
-	res, err := svc.Statements.List(sessionID).Do()
-	pp.Println(res, err)
-}
-
-func StatementsGet(sessionID, statementID int) *livy.Statement {
-	svc := livy.NewService(context.Background())
-	res, err := svc.Statements.Get(sessionID, statementID).Do()
-	pp.Println(res, err)
-	return res
-}
-
-func StatementsWait(sessionID, statementID int) *livy.Statement {
-	t := time.NewTicker(5 * time.Second)
-	defer t.Stop()
-
-	for range t.C {
-		stmt := StatementsGet(sessionID, statementID)
-		b, _ := stmt.Output.Data.MarshalJSON()
-		pp.Println(string(b))
-		if stmt.State == livy.StatementState_Available {
-			return stmt
-		}
-	}
-
-	return nil
-}
-
-func StatementsInsert(sessionID int) *livy.Statement {
-	svc := livy.NewService(context.Background())
-	letter := "val NUM_SAMPLES = 100000;\n" +
-		"val count = sc.parallelize(1 to NUM_SAMPLES).map { i => \n" +
-		"val x = Math.random();\n" +
-		"val y = Math.random();\n" +
-		"if (x*x + y*y < 1) 1 else 0\n" +
-		"}.reduce(_ + _);\n" +
-		"println(\"Pi is roughly \" + 4.0 * count / NUM_SAMPLES)"
-
-	letter = "import com.locona.livy._\n" +
-		"val ds = WordCount.executor()\n" +
-		"ds.show(false)\n" +
-		"ds.printSchema"
-	res, err := svc.Statements.Insert(sessionID, &livy.InsertStatementRequest{
-		Code: dedent.Dedent(letter),
-	}).Do()
-	pp.Println(res, err)
-	return res
-}
-
-func BatchesList() {
-	svc := livy.NewService(context.Background())
-	res, err := svc.Batches.List().Do()
-	pp.Println(res, err)
-}
-
-// Stat is exported out of golang convention, rather than necessity
-
-func rootPath() (string, error) {
-	path, err := exec.Command("git", "rev-parse", "--show-toplevel").Output()
-	if err != nil {
-		return "", err
-	}
-	fmt.Println(string(path))
-	return strings.TrimSpace(string(path)), nil
-}
-
-func main() {
-	rootPath, err := rootPath()
-	if err != nil {
-		panic(err)
-	}
-
-	jar := "/jars/target/scala-2.11/root-assembly-1.0.0-SNAPSHOT.jar"
-	jarPath := fmt.Sprintf("%v/%v", rootPath, jar)
-	SessionsInsert(jarPath)
-
-	sessionID := 2
-	// sessionID = session.ID
-	// session := SessionsGet(sessionID)
-	// SessionsDelete(sessionID)
-	// SessionsState(sessionID)
-	// SessionsLog(sessionID)
-
-	// Statement
-	// StatementsList(sessionID)
-	statement := StatementsInsert(sessionID)
-	statement = StatementsWait(sessionID, statement.ID)
-	pp.Println(statement)
-}
diff --git a/gensupport/json.go b/gensupport/json.go
deleted file mode 100644
index c7a34d7..0000000
--- a/gensupport/json.go
+++ /dev/null
@@ -1,20 +0,0 @@
-package gensupport
-
-import (
-	"bytes"
-	"encoding/json"
-	"io"
-	"strings"
-)
-
-func JSONReader(v interface{}) (io.Reader, error) {
-	buf := new(bytes.Buffer)
-	encoder := json.NewEncoder(buf)
-	encoder.SetEscapeHTML(false)
-	err := encoder.Encode(v)
-	if err != nil {
-		return nil, err
-	}
-
-	return bytes.NewBufferString(strings.TrimRight(buf.String(), "\n")), nil
-}
diff --git a/gensupport/params.go b/gensupport/params.go
deleted file mode 100644
index b340def..0000000
--- a/gensupport/params.go
+++ /dev/null
@@ -1,38 +0,0 @@
-package gensupport
-
-import (
-	"net/url"
-)
-
-// URLParams is a simplified replacement for url.Values
-// that safely builds up URL parameters for encoding.
-type URLParams map[string][]string
-
-// Get returns the first value for the given key, or "".
-func (u URLParams) Get(key string) string {
-	vs := u[key]
-	if len(vs) == 0 {
-		return ""
-	}
-	return vs[0]
-}
-
-// Set sets the key to value.
-// It replaces any existing values.
-func (u URLParams) Set(key, value string) {
-	u[key] = []string{value}
-}
-
-// SetMulti sets the key to an array of values.
-// It replaces any existing values.
-// Note that values must not be modified after calling SetMulti
-// so the caller is responsible for making a copy if necessary.
-func (u URLParams) SetMulti(key string, values []string) {
-	u[key] = values
-}
-
-// Encode encodes the values into ``URL encoded'' form
-// ("bar=baz&foo=quux") sorted by key.
-func (u URLParams) Encode() string {
-	return url.Values(u).Encode()
-}
diff --git a/gensupport/send.go b/gensupport/send.go
deleted file mode 100644
index 90b57ae..0000000
--- a/gensupport/send.go
+++ /dev/null
@@ -1,43 +0,0 @@
-package gensupport
-
-import (
-	"context"
-	"encoding/json"
-	"net/http"
-)
-
-func SendRequest(client *http.Client, req *http.Request) (*http.Response, error) {
-	reqHeaders := make(http.Header)
-	reqHeaders.Set("Content-Type", "application/json")
-	req.Header = reqHeaders
-	return client.Do(req)
-
-	// TODO: Send request.
-	// return send(ctx, client, req)
-}
-
-func send(ctx context.Context, client *http.Client, req *http.Request) (*http.Response, error) {
-	if client == nil {
-		client = http.DefaultClient
-	}
-	resp, err := client.Do(req.WithContext(ctx))
-	// If we got an error, and the context has been canceled,
-	// the context's error is probably more useful.
-	if err != nil {
-		select {
-		case <-ctx.Done():
-			err = ctx.Err()
-		default:
-		}
-	}
-	return resp, err
-}
-
-// DecodeResponse decodes the body of res into target. If there is no body,
-// target is unchanged.
-func DecodeResponse(target interface{}, res *http.Response) error {
-	if res.StatusCode == http.StatusNoContent {
-		return nil
-	}
-	return json.NewDecoder(res.Body).Decode(target)
-}
diff --git a/go.mod b/go.mod
index c82288e..149fd6c 100644
--- a/go.mod
+++ b/go.mod
@@ -1,11 +1,11 @@
 module github.com/3-shake/livy-go
 
-go 1.12
+go 1.14
 
 require (
-	github.com/k0kubun/colorstring v0.0.0-20150214042306-9440f1994b88 // indirect
+	github.com/google/uuid v1.1.1
 	github.com/k0kubun/pp v3.0.1+incompatible
 	github.com/lithammer/dedent v1.1.0
-	github.com/mattn/go-colorable v0.1.4 // indirect
-	golang.org/x/sys v0.0.0-20190412213103-97732733099d // indirect
+	github.com/mattn/go-colorable v0.1.6 // indirect
+	github.com/stretchr/testify v1.5.1
 )
diff --git a/go.sum b/go.sum
index 8bf7e9d..1e4c6be 100644
--- a/go.sum
+++ b/go.sum
@@ -1,13 +1,24 @@
-github.com/k0kubun/colorstring v0.0.0-20150214042306-9440f1994b88 h1:uC1QfSlInpQF+M0ao65imhwqKnz3Q2z/d8PWZRMQvDM=
-github.com/k0kubun/colorstring v0.0.0-20150214042306-9440f1994b88/go.mod h1:3w7q1U84EfirKl04SVQ/s7nPm1ZPhiXd34z40TNz36k=
+github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/google/uuid v1.1.1 h1:Gkbcsh/GbpXz7lPftLA3P6TYMwjCLYm83jiFQZF/3gY=
+github.com/google/uuid v1.1.1/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/k0kubun/pp v1.3.0 h1:r9td75hcmetrcVbmsZRjnxcIbI9mhm+/N6iWyG4TWe0=
 github.com/k0kubun/pp v3.0.1+incompatible h1:3tqvf7QgUnZ5tXO6pNAZlrvHgl6DvifjDrd9g2S9Z40=
 github.com/k0kubun/pp v3.0.1+incompatible/go.mod h1:GWse8YhT0p8pT4ir3ZgBbfZild3tgzSScAn6HmfYukg=
 github.com/lithammer/dedent v1.1.0 h1:VNzHMVCBNG1j0fh3OrsFRkVUwStdDArbgBWoPAffktY=
 github.com/lithammer/dedent v1.1.0/go.mod h1:jrXYCQtgg0nJiN+StA2KgR7w6CiQNv9Fd/Z9BP0jIOc=
-github.com/mattn/go-colorable v0.1.4 h1:snbPLB8fVfU9iwbbo30TPtbLRzwWu6aJS6Xh4eaaviA=
-github.com/mattn/go-colorable v0.1.4/go.mod h1:U0ppj6V5qS13XJ6of8GYAs25YV2eR4EVcfRqFIhoBtE=
-github.com/mattn/go-isatty v0.0.8 h1:HLtExJ+uU2HOZ+wI0Tt5DtUDrx8yhUqDcp7fYERX4CE=
-github.com/mattn/go-isatty v0.0.8/go.mod h1:Iq45c/XA43vh69/j3iqttzPXn0bhXyGjM0Hdxcsrc5s=
-golang.org/x/sys v0.0.0-20190222072716-a9d3bda3a223/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
-golang.org/x/sys v0.0.0-20190412213103-97732733099d h1:+R4KGOnez64A81RvjARKc4UT5/tI9ujCIVX+P5KiHuI=
-golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+github.com/mattn/go-colorable v0.1.6 h1:6Su7aK7lXmJ/U79bYtBjLNaha4Fs1Rg9plHpcH+vvnE=
+github.com/mattn/go-colorable v0.1.6/go.mod h1:u6P/XSegPjTcexA+o6vUJrdnUu04hMope9wVRipJSqc=
+github.com/mattn/go-isatty v0.0.12 h1:wuysRhFDzyxgEmMf5xjvJ2M9dZoWAXNNr5LSBS7uHXY=
+github.com/mattn/go-isatty v0.0.12/go.mod h1:cbi8OIDigv2wuxKPP5vlRcQ1OAZbq2CE4Kysco4FUpU=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.5.1 h1:nOGnQDM7FYENwehXlg/kFVnos3rEvtKTjRvOWSzb6H4=
+github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
+golang.org/x/sys v0.0.0-20200116001909-b77594299b42/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200223170610-d5e6a3e2c0ae h1:/WDfKMnPU+m5M4xB+6x4kaepxRw6jWvR5iDRdvjHgy8=
+golang.org/x/sys v0.0.0-20200223170610-d5e6a3e2c0ae/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
+gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
diff --git a/httputil.go b/httputil.go
new file mode 100644
index 0000000..f02d471
--- /dev/null
+++ b/httputil.go
@@ -0,0 +1,48 @@
+package livy
+
+import (
+	"bytes"
+	"encoding/json"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"strings"
+)
+
+type ErrorResponse struct {
+	ErrorMessage string `json:"error_message"`
+}
+
+func (err *ErrorResponse) Error() string {
+	return err.ErrorMessage
+}
+
+func JSONReader(v interface{}) (io.Reader, error) {
+	buf := new(bytes.Buffer)
+	encoder := json.NewEncoder(buf)
+	encoder.SetEscapeHTML(false)
+	err := encoder.Encode(v)
+	if err != nil {
+		return nil, err
+	}
+
+	return bytes.NewBufferString(strings.TrimRight(buf.String(), "\n")), nil
+}
+
+func SendRequest(client *http.Client, req *http.Request) (*http.Response, error) {
+	reqHeaders := make(http.Header)
+	reqHeaders.Set("Content-Type", "application/json")
+	req.Header = reqHeaders
+	return client.Do(req)
+}
+
+// DecodeResponse decodes the body of res into target. If there is no body,
+// target is unchanged.
+func DecodeResponse(target interface{}, res *http.Response) error {
+	if res.StatusCode >= http.StatusBadRequest {
+		b, _ := ioutil.ReadAll(res.Body)
+		return &ErrorResponse{string(b)}
+	}
+
+	return json.NewDecoder(res.Body).Decode(target)
+}
diff --git a/livy_test.go b/livy_test.go
new file mode 100644
index 0000000..734f553
--- /dev/null
+++ b/livy_test.go
@@ -0,0 +1,32 @@
+package livy_test
+
+import (
+	"context"
+	"os"
+	"os/exec"
+	"strings"
+	"testing"
+
+	"github.com/3-shake/livy-go"
+)
+
+var service = livy.NewService(context.Background())
+
+var RootPath string
+
+func TestMain(m *testing.M) {
+	rootPath()
+
+	exitVal := m.Run()
+
+	os.Exit(exitVal)
+}
+
+func rootPath() {
+	path, err := exec.Command("git", "rev-parse", "--show-toplevel").Output()
+	if err != nil {
+		panic(err)
+	}
+
+	RootPath = strings.TrimSpace(string(path))
+}
diff --git a/service.go b/service.go
index 222735a..bc1c55f 100644
--- a/service.go
+++ b/service.go
@@ -21,7 +21,6 @@ type Service struct {
 
 func NewService(ctx context.Context) *Service {
 	return New(http.DefaultClient)
-
 }
 
 func New(client *http.Client) *Service {
diff --git a/session.go b/session.go
index 4a6ffa3..2ba81e1 100644
--- a/session.go
+++ b/session.go
@@ -4,8 +4,6 @@ import (
 	"fmt"
 	"io"
 	"net/http"
-
-	"github.com/3-shake/livy-go/gensupport"
 )
 
 const (
@@ -45,16 +43,13 @@ type SessionsService struct {
 }
 
 type Sessions struct {
-	s     *Service
 	From  int        `json:"from"`
 	Size  int        `json:"size"`
 	Items []*Session `json:"sessions"`
 }
 
 type SessionsListCall struct {
-	s    *Service
-	from int
-	size int
+	s *Service
 }
 
 type Session struct {
@@ -92,7 +87,7 @@ func (c *SessionsListCall) Do() (*Sessions, error) {
 	}
 
 	sessions := &Sessions{}
-	err = gensupport.DecodeResponse(sessions, res)
+	err = DecodeResponse(sessions, res)
 	if err != nil {
 		return nil, err
 	}
@@ -107,7 +102,7 @@ func (c *SessionsListCall) doRequest() (*http.Response, error) {
 		return nil, err
 	}
 
-	return gensupport.SendRequest(c.s.client, req)
+	return SendRequest(c.s.client, req)
 }
 
 type SessionsGetCall struct {
@@ -132,7 +127,7 @@ func (c *SessionsGetCall) Do() (*Session, error) {
 
 	session := &Session{}
 
-	err = gensupport.DecodeResponse(session, res)
+	err = DecodeResponse(session, res)
 	if err != nil {
 		return nil, err
 	}
@@ -149,7 +144,7 @@ func (c *SessionsGetCall) doRequest() (*http.Response, error) {
 		return nil, err
 	}
 
-	return gensupport.SendRequest(c.s.client, req)
+	return SendRequest(c.s.client, req)
 }
 
 type InsertSessionRequest struct {
@@ -205,7 +200,7 @@ func (c *SessionsInsertCall) Do() (*Session, error) {
 	}
 
 	session := &Session{}
-	err = gensupport.DecodeResponse(session, res)
+	err = DecodeResponse(session, res)
 	if err != nil {
 		return nil, err
 	}
@@ -215,9 +210,8 @@ func (c *SessionsInsertCall) Do() (*Session, error) {
 
 func (c *SessionsInsertCall) doRequest() (*http.Response, error) {
 	url := c.s.BasePath + "/sessions"
-	var body io.Reader = nil
 
-	body, err := gensupport.JSONReader(c.insertSessionRequest)
+	body, err := JSONReader(c.insertSessionRequest)
 	if err != nil {
 		return nil, err
 	}
@@ -227,7 +221,7 @@ func (c *SessionsInsertCall) doRequest() (*http.Response, error) {
 		return nil, err
 	}
 
-	return gensupport.SendRequest(c.s.client, req)
+	return SendRequest(c.s.client, req)
 }
 
 type SessionsDeleteCall struct {
@@ -262,7 +256,7 @@ func (c *SessionsDeleteCall) doRequest() (*http.Response, error) {
 		return nil, err
 	}
 
-	return gensupport.SendRequest(c.s.client, req)
+	return SendRequest(c.s.client, req)
 }
 
 type SessionStateResponse struct {
@@ -292,7 +286,7 @@ func (c *SessionsGetStateCall) Do() (*SessionStateResponse, error) {
 
 	sessionState := &SessionStateResponse{}
 
-	err = gensupport.DecodeResponse(sessionState, res)
+	err = DecodeResponse(sessionState, res)
 	if err != nil {
 		return nil, err
 	}
@@ -309,7 +303,7 @@ func (c *SessionsGetStateCall) doRequest() (*http.Response, error) {
 		return nil, err
 	}
 
-	return gensupport.SendRequest(c.s.client, req)
+	return SendRequest(c.s.client, req)
 }
 
 type SessionLogResponse struct {
@@ -341,7 +335,7 @@ func (c *SessionsLogCall) Do() (*SessionLogResponse, error) {
 
 	sessionLog := &SessionLogResponse{}
 
-	err = gensupport.DecodeResponse(sessionLog, res)
+	err = DecodeResponse(sessionLog, res)
 	if err != nil {
 		return nil, err
 	}
@@ -358,5 +352,5 @@ func (c *SessionsLogCall) doRequest() (*http.Response, error) {
 		return nil, err
 	}
 
-	return gensupport.SendRequest(c.s.client, req)
+	return SendRequest(c.s.client, req)
 }
diff --git a/session_test.go b/session_test.go
new file mode 100644
index 0000000..3e2229c
--- /dev/null
+++ b/session_test.go
@@ -0,0 +1,82 @@
+package livy_test
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/google/uuid"
+	"github.com/k0kubun/pp"
+	"github.com/stretchr/testify/assert"
+
+	"github.com/3-shake/livy-go"
+)
+
+func TestSession_List(t *testing.T) {
+	_, _ = insert()
+	res, err := service.Sessions.List().Do()
+	pp.Println(res, err)
+
+	assert.Equal(t, err, nil)
+}
+
+func TestSession_Get(t *testing.T) {
+	sess, _ := insert()
+	res, err := service.Sessions.Get(sess.ID).Do()
+	pp.Println(res, err)
+
+	assert.Equal(t, err, nil)
+}
+
+func TestSession_Insert(t *testing.T) {
+	_, err := insert()
+
+	pp.Println(err)
+
+	assert.Equal(t, err, nil)
+}
+
+func TestSession_Delete(t *testing.T) {
+	sess, _ := insert()
+	err := service.Sessions.Delete(sess.ID).Do()
+
+	pp.Println(err)
+
+	assert.Equal(t, err, nil)
+}
+
+func TestSession_State(t *testing.T) {
+	sess, _ := insert()
+	res, err := service.Sessions.State(sess.ID).Do()
+
+	pp.Println(res, err)
+
+	assert.Equal(t, err, nil)
+}
+
+func TestSession_Log(t *testing.T) {
+	sess, _ := insert()
+	res, err := service.Sessions.Log(sess.ID).Do()
+
+	pp.Println(res, err)
+
+	assert.Equal(t, err, nil)
+}
+
+func insert() (*livy.Session, error) {
+	rootPath := RootPath
+
+	jar := "/jars/target/scala-2.11/root-assembly-1.0.0-SNAPSHOT.jar"
+	jarPath := fmt.Sprintf("%v/%v", rootPath, jar)
+
+	uid := uuid.New()
+	return service.Sessions.Insert(&livy.InsertSessionRequest{
+		Name: uid.String(),
+		Kind: livy.SessionKind_Spark,
+		Jars: []string{
+			fmt.Sprintf("local://%v", jarPath),
+		},
+		Conf: map[string]string{
+			"spark.driver.extraClassPath": jarPath,
+		},
+	}).Do()
+}
diff --git a/statement.go b/statement.go
index 02e2529..b17b11c 100644
--- a/statement.go
+++ b/statement.go
@@ -5,8 +5,7 @@ import (
 	"fmt"
 	"io"
 	"net/http"
-
-	"github.com/3-shake/livy-go/gensupport"
+	"time"
 )
 
 const (
@@ -20,7 +19,10 @@ const (
 
 type StatementState string
 
-type Statements []*Statement
+type Statements struct {
+	TotalStatements int          `json:"total_statements"`
+	Statements      []*Statement `json:"statements"`
+}
 
 type Statement struct {
 	ID     int
@@ -62,7 +64,7 @@ func (c *StatementsListCall) Do() (*Statements, error) {
 	}
 
 	statements := &Statements{}
-	err = gensupport.DecodeResponse(statements, res)
+	err = DecodeResponse(statements, res)
 	if err != nil {
 		return nil, err
 	}
@@ -77,7 +79,7 @@ func (c *StatementsListCall) doRequest() (*http.Response, error) {
 		return nil, err
 	}
 
-	return gensupport.SendRequest(c.s.client, req)
+	return SendRequest(c.s.client, req)
 }
 
 type StatementsGetCall struct {
@@ -101,7 +103,7 @@ func (c *StatementsGetCall) Do() (*Statement, error) {
 	}
 
 	statement := &Statement{}
-	err = gensupport.DecodeResponse(statement, res)
+	err = DecodeResponse(statement, res)
 
 	if err != nil {
 		return nil, err
@@ -117,7 +119,7 @@ func (c *StatementsGetCall) doRequest() (*http.Response, error) {
 		return nil, err
 	}
 
-	return gensupport.SendRequest(c.s.client, req)
+	return SendRequest(c.s.client, req)
 }
 
 type InsertStatementRequest struct {
@@ -129,12 +131,14 @@ type StatementsInsertCall struct {
 	s                      *Service
 	sessionID              int
 	insertStatementRequest *InsertStatementRequest
+	wait                   bool
 }
 
-func (r *StatementsService) Insert(sessionID int, insertStatementRequest *InsertStatementRequest) *StatementsInsertCall {
+func (r *StatementsService) Insert(sessionID int, insertStatementRequest *InsertStatementRequest, wait bool) *StatementsInsertCall {
 	c := &StatementsInsertCall{s: r.s}
 	c.sessionID = sessionID
 	c.insertStatementRequest = insertStatementRequest
+	c.wait = wait
 
 	return c
 }
@@ -146,16 +150,34 @@ func (c *StatementsInsertCall) Do() (*Statement, error) {
 	}
 
 	statement := &Statement{}
-	err = gensupport.DecodeResponse(statement, res)
+	err = DecodeResponse(statement, res)
 	if err != nil {
 		return nil, err
 	}
-	return statement, nil
+	if !c.wait {
+		return statement, nil
+	}
+
+	availableStmt := &Statement{}
+	t := time.NewTicker(5 * time.Second)
+	defer t.Stop()
+	for range t.C {
+		availableStmt, err = c.s.Statements.Get(c.sessionID, statement.ID).Do()
+		if err != nil {
+			break
+		}
+
+		if availableStmt.State == StatementState_Available {
+			break
+		}
+	}
+
+	return availableStmt, err
 }
 
 func (c *StatementsInsertCall) doRequest() (*http.Response, error) {
 	url := c.s.BasePath + fmt.Sprintf("/sessions/%v/statements", c.sessionID)
-	body, err := gensupport.JSONReader(c.insertStatementRequest)
+	body, err := JSONReader(c.insertStatementRequest)
 	if err != nil {
 		return nil, err
 	}
@@ -165,5 +187,5 @@ func (c *StatementsInsertCall) doRequest() (*http.Response, error) {
 		return nil, err
 	}
 
-	return gensupport.SendRequest(c.s.client, req)
+	return SendRequest(c.s.client, req)
 }
diff --git a/statement_test.go b/statement_test.go
new file mode 100644
index 0000000..96599c1
--- /dev/null
+++ b/statement_test.go
@@ -0,0 +1,107 @@
+package livy_test
+
+import (
+	"testing"
+	"time"
+
+	"github.com/k0kubun/pp"
+	"github.com/lithammer/dedent"
+	"github.com/stretchr/testify/assert"
+
+	"github.com/3-shake/livy-go"
+)
+
+func TestStatement_List(t *testing.T) {
+	sess, _ := insert()
+
+	sessionWait(sess.ID)
+	_, _ = statementInsert(sess.ID)
+
+	res, err := service.Statements.List(sess.ID).Do()
+
+	pp.Println(res, err)
+
+	assert.Equal(t, err, nil)
+}
+
+func TestStatement_Get(t *testing.T) {
+	sess, _ := insert()
+
+	sessionWait(sess.ID)
+	stmt, _ := statementInsert(sess.ID)
+
+	res, err := service.Statements.Get(sess.ID, stmt.ID).Do()
+
+	pp.Println(res, err)
+
+	assert.Equal(t, err, nil)
+}
+
+func TestStatement_Insert(t *testing.T) {
+	sess, _ := insert()
+
+	sessionWait(sess.ID)
+	res, err := statementInsert(sess.ID)
+	pp.Println(res, err)
+
+	assert.Equal(t, err, nil)
+	assert.Equal(t, res.State, livy.StatementState_Waiting)
+}
+
+func TestStatement_Insert_Wait(t *testing.T) {
+	sess, _ := insert()
+
+	sessionWait(sess.ID)
+	letter := "val NUM_SAMPLES = 100000;\n" +
+		"val count = sc.parallelize(1 to NUM_SAMPLES).map { i => \n" +
+		"val x = Math.random();\n" +
+		"val y = Math.random();\n" +
+		"if (x*x + y*y < 1) 1 else 0\n" +
+		"}.reduce(_ + _);\n" +
+		"println(\"Pi is roughly \" + 4.0 * count / NUM_SAMPLES)"
+
+	letter = "import com.locona.livy._\n" +
+		"val ds = WordCount.executor()\n" +
+		"ds.show(false)\n" +
+		"ds.printSchema"
+
+	res, err := service.Statements.Insert(sess.ID, &livy.InsertStatementRequest{
+		Code: dedent.Dedent(letter),
+	}, true).Do()
+
+	pp.Println(res, err)
+
+	assert.Equal(t, err, nil)
+	assert.Equal(t, res.State, livy.StatementState_Available)
+}
+
+func sessionWait(sessionID int) {
+	t := time.NewTicker(5 * time.Second)
+	defer t.Stop()
+
+	for range t.C {
+		res, _ := service.Sessions.State(sessionID).Do()
+		if res.State == livy.SessionState_Idle {
+			return
+		}
+	}
+}
+
+func statementInsert(sessionID int) (*livy.Statement, error) {
+	letter := "val NUM_SAMPLES = 100000;\n" +
+		"val count = sc.parallelize(1 to NUM_SAMPLES).map { i => \n" +
+		"val x = Math.random();\n" +
+		"val y = Math.random();\n" +
+		"if (x*x + y*y < 1) 1 else 0\n" +
+		"}.reduce(_ + _);\n" +
+		"println(\"Pi is roughly \" + 4.0 * count / NUM_SAMPLES)"
+
+	letter = "import com.locona.livy._\n" +
+		"val ds = WordCount.executor()\n" +
+		"ds.show(false)\n" +
+		"ds.printSchema"
+
+	return service.Statements.Insert(sessionID, &livy.InsertStatementRequest{
+		Code: dedent.Dedent(letter),
+	}, false).Do()
+}