Removing some warning:

src/main/java/org/zeromq/ZPoller.java

@@ -10,7 +10,6 @@
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Objects;
-import java.util.Optional;
 import java.util.Set;
 import java.util.stream.Collectors;
 
@@ -333,7 +332,6 @@ private ZPoller(final ItemCreator creator, final ZContext context, final Selecto
         Objects.requireNonNull(selector, "Selector is mandatory for ZPoller");
 
         this.creator = creator;
-        this.context = Optional.ofNullable(context);
         this.selector = selector;
         items = new HashMap<>();
         all = createContainer(0);
@@ -743,14 +741,9 @@ public void close() throws IOException
      */
     public void destroy()
     {
-        // if we created the selector,
-        // it is our responsibility to close it.
-        context.ifPresent(ctx -> ctx.closeSelector(selector));
+        // Nothing to do
     }
 
-    // optional context for the poller.
-    private final Optional<ZContext> context;
-
     // selector used for polling
     private final Selector selector;
 

src/main/java/org/zeromq/ZStar.java

@@ -453,14 +453,6 @@ protected ZAgent agent(Socket phone, String secret)
         return ZAgent.Creator.create(phone, secret);
     }
 
-    /**
-     * @return the context. Never null. If provided context in constructor was null, returns the auto-generated context for that star.
-     */
-    private ZContext context()
-    {
-        return context;
-    }
-
     // the plateau where the acting will take place (stage and backstage), or
     // the forked runnable containing the loop processing all messages in the background
     private static final class Plateau implements IAttachedRunnable, Exit

src/main/java/zmq/ZMQ.java

@@ -296,12 +296,6 @@ private static void destroyContext(Ctx ctx)
         ctx.terminate();
     }
 
-    private static void shutdownContext(Ctx ctx)
-    {
-        checkContext(ctx);
-        ctx.shutdown();
-    }
-
     public static void setContextOption(Ctx ctx, int option, int optval)
     {
         checkContext(ctx);

src/main/java/zmq/io/net/tcp/SocksConnecter.java

@@ -9,9 +9,6 @@
 // TODO continue socks connecter
 public class SocksConnecter extends TcpConnecter
 {
-    //  Method ID
-    private static final int SOCKS_NO_AUTH_REQUIRED = 0;
-
     private Address proxyAddress;
 
     private enum Status

src/main/java/zmq/io/net/tcp/TcpConnecter.java

@@ -46,9 +46,6 @@ public class TcpConnecter extends Own implements IPollEvents
     //  Current reconnect ivl, updated for backoff strategy
     private int currentReconnectIvl;
 
-    // String representation of endpoint to connect to
-    private final String endpoint;
-
     // Socket
     private final SocketBase socket;
 
@@ -67,7 +64,6 @@ public TcpConnecter(IOThread ioThread, SessionBase session, final Options option
         assert (this.addr != null);
         //        assert (NetProtocol.tcp.equals(this.addr.protocol())); // not always true, as ipc is emulated by tcp
 
-        endpoint = this.addr.toString();
         socket = session.getSocket();
     }
 

src/main/java/zmq/io/net/tipc/TipcListener.java

@@ -3,13 +3,10 @@
 import zmq.Options;
 import zmq.SocketBase;
 import zmq.io.IOThread;
-import zmq.io.net.ipc.IpcAddress;
 import zmq.io.net.tcp.TcpListener;
 
 public class TipcListener extends TcpListener
 {
-    private IpcAddress address;
-
     public TipcListener(IOThread ioThread, SocketBase socket, final Options options)
     {
         super(ioThread, socket, options);