void close(Dockable dockable) {
		int count = getComponentCount();
		for (int i = 0; i < count; i++) {
			Component child = getComponent(i);
			if (child instanceof DockTab) {
				if (((DockTab) child).getDockable() == dockable) {
					remove(child);
					return;
				}
			}
		}
	}