public void SetupGUI()
 {
     backgroundStyle = new GUIStyle(GUI.skin.box);
     backgroundStyle.contentOffset = new Vector2(2f, 2f);
     expandRight   = ResourceManager.LoadTexture("Textures/expandRight.png");
     itemHeight    = GUI.skin.label.CalcHeight(new GUIContent("text"), 100f);
     selectedLabel = new GUIStyle(GUI.skin.label);
     selectedLabel.normal.background = RTEditorGUI.ColorToTex(1, new Color(0.4f, 0.4f, 0.4f));
 }