diff --git a/src/main/java/pl/com/it_crowd/youtrack/api/Command.java b/src/main/java/pl/com/it_crowd/youtrack/api/Command.java
index 83d45e8..d2d2c06 100644
--- a/src/main/java/pl/com/it_crowd/youtrack/api/Command.java
+++ b/src/main/java/pl/com/it_crowd/youtrack/api/Command.java
@@ -59,9 +59,9 @@ public class Command {
         return state(state.getCommandValue());
     }
 
-    private Command command(Fields command, String argument)
+    protected Command command(Commander commander, String argument)
     {
-        this.command.append(" ").append(command.getCommand()).append(" ").append(argument);
+        this.command.append(" ").append(commander.getCommand()).append(" ").append(argument);
         return this;
     }
 }
diff --git a/src/main/java/pl/com/it_crowd/youtrack/api/Commander.java b/src/main/java/pl/com/it_crowd/youtrack/api/Commander.java
new file mode 100644
index 0000000..cc88b98
--- /dev/null
+++ b/src/main/java/pl/com/it_crowd/youtrack/api/Commander.java
@@ -0,0 +1,7 @@
+package pl.com.it_crowd.youtrack.api;
+
+public interface Commander {
+// -------------------------- OTHER METHODS --------------------------
+
+    String getCommand();
+}
diff --git a/src/main/java/pl/com/it_crowd/youtrack/api/defaults/Fields.java b/src/main/java/pl/com/it_crowd/youtrack/api/defaults/Fields.java
index ec7b932..ad02a7b 100644
--- a/src/main/java/pl/com/it_crowd/youtrack/api/defaults/Fields.java
+++ b/src/main/java/pl/com/it_crowd/youtrack/api/defaults/Fields.java
@@ -1,6 +1,8 @@
 package pl.com.it_crowd.youtrack.api.defaults;
 
-public enum Fields {
+import pl.com.it_crowd.youtrack.api.Commander;
+
+public enum Fields implements Commander {
     assignee,
     issueId("issue id"),
     state,