done

src/main/java/com/zipcodewilmington/generic/group/Group.java

 import com.zipcodewilmington.generic.identifiables.IdentifiableInterface;
 
 import java.io.Serializable;
+import java.util.Collection;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.function.Predicate;
 
 /**
  * @author leon on 06/12/2018.
  */
-public class Group<ChangeThisTypeRespectively,ChangeThisOneToo> extends AbstractGroup{
+public class Group<S extends Serializable,I extends IdentifiableInterface<S>> extends AbstractGroup{
+
+    Map<S,I> map;
+
+    public Group(){
+         map = new HashMap<>();
+    }
+
     @Override
     public Integer count() {
-        return null;
+        return map.size();
     }
 
     @Override