public override void OnInspectorGUI()
        {
            if (this.stateMachine == null)
            {
                return;
            }

            this.serializedObject.Update();

            GUILayoutUtils.VerticalSpace(8);

            DrawGraphButton();

            GUILayoutUtils.VerticalSpace(4);

            DrawStateList();
            DrawTransitionList();

            this.serializedObject.ApplyModifiedProperties();
        }