private DockLayout findLayoutInternal(DockContainer dc) {
		for (DockLayoutNode child : mChildren) {
			if (child instanceof DockContainer) {
				if (child == dc) {
					return this;
				}
			} else if (child instanceof DockLayout) {
				DockLayout layout = ((DockLayout) child).findLayoutInternal(dc);
				if (layout != null) {
					return layout;
				}
			}
		}
		return null;
	}