Implement LinkedMap class

force-app/main/default/classes/LinkedMap.cls

@@ -0,0 +1,35 @@
+public class LinkedMap {
+    private Map<Set<String>, List<Object>> linkedMap;
+
+    public LinkedMap() {
+        this.linkedMap = new Map<Set<String>, List<Object>>();
+    }
+
+    public void put(Set<String> keys, List<Object> values) {
+        if (this.linkedMap.containsKey(keys)) {
+            this.linkedMap.get(keys).addAll(values);
+        } else {
+            this.linkedMap.put(keys, values);
+        }
+    }
+
+    public List<Object> get(Set<String> keys) {
+        return this.linkedMap.get(keys);
+    }
+
+    public List<Object> remove(Set<String> keys) {
+        return this.linkedMap.remove(keys);
+    }
+
+    public Boolean containsKey(Set<String> keys) {
+        return this.linkedMap.containsKey(keys);
+    }
+
+    public Set<Set<String>> keySet() {
+        return this.linkedMap.keySet();
+    }
+
+    public List<List<Object>> values() {
+        return this.linkedMap.values();
+    }
+}

force-app/main/default/classes/LinkedMapTests.cls

@@ -0,0 +1,50 @@
+@isTest
+public class LinkedMapTests {
+    @isTest
+    static void testPut() {
+        LinkedMap map = new LinkedMap();
+        map.put(new Set<String>{'key1'}, new List<Object>{'value1'});
+        System.assertEquals(map.get(new Set<String>{'key1'}), new List<Object>{'value1'});
+
+        map.put(new Set<String>{'key1'}, new List<Object>{'value2'});
+        System.assertEquals(map.get(new Set<String>{'key1'}), new List<Object>{'value1', 'value2'});
+    }
+
+    @isTest
+    static void testGet() {
+        LinkedMap map = new LinkedMap();
+        map.put(new Set<String>{'key1'}, new List<Object>{'value1'});
+        System.assertEquals(map.get(new Set<String>{'key1'}), new List<Object>{'value1'});
+        System.assertEquals(map.get(new Set<String>{'key2'}), null);
+    }
+
+    @isTest
+    static void testRemove() {
+        LinkedMap map = new LinkedMap();
+        map.put(new Set<String>{'key1'}, new List<Object>{'value1'});
+        System.assertEquals(map.remove(new Set<String>{'key1'}), new List<Object>{'value1'});
+        System.assertEquals(map.remove(new Set<String>{'key1'}), null);
+    }
+
+    @isTest
+    static void testContainsKey() {
+        LinkedMap map = new LinkedMap();
+        map.put(new Set<String>{'key1'}, new List<Object>{'value1'});
+        System.assertEquals(map.containsKey(new Set<String>{'key1'}), true);
+        System.assertEquals(map.containsKey(new Set<String>{'key2'}), false);
+    }
+
+    @isTest
+    static void testKeySet() {
+        LinkedMap map = new LinkedMap();
+        map.put(new Set<String>{'key1'}, new List<Object>{'value1'});
+        System.assertEquals(map.keySet(), new Set<Set<String>>{new Set<String>{'key1'}});
+    }
+
+    @isTest
+    static void testValues() {
+        LinkedMap map = new LinkedMap();
+        map.put(new Set<String>{'key1'}, new List<Object>{'value1'});
+        System.assertEquals(map.values(), new List<List<Object>>{new List<Object>{'value1'}});
+    }
+}