在Eclipse插件开发中如何在Eclipse导入菜单项之前创建上下文菜单

<extension point="org.eclipse.ui.contextMenus">
    <contextMenu id="com.example.contextmenu">
        <command commandId="com.example.commands.myCommand" label="My Command" style="push">
            <visibleWhen checkEnabled="false">
                <with variable="activeEditorId">
                    <equals value="org.eclipse.ui.DefaultTextEditor"/>
                </with>
            </visibleWhen>
        </command>
    </contextMenu>
</extension>

<extension point="org.eclipse.ui.commands">
    <command id="com.example.commands.myCommand" name="My Command"/>
</extension>

public class MyCommandHandler extends AbstractHandler {
    @Override
    public Object execute(ExecutionEvent event) throws ExecutionException {
        MessageDialog.openInformation(
            HandlerUtil.getActiveShell(event),
            "My Command",
            "Hello, Eclipse!");
        return null;
    }
}

<extension point="org.eclipse.ui.handlers">
    <handler commandId="com.example.commands.myCommand" class="com.example.MyCommandHandler"/>
</extension>