NavigationHelpButton

Name	Type	Description
options	object	Object with the following properties: Name Type Default Description container Element | string 将包含该部件（widget）的 DOM 元素或 ID。 instructionsInitiallyVisible boolean false optional 如果导航说明初始时应可见则为 true；否则为 false。

Throws:

• DeveloperError : 文档中不存在 id 为 "container" 的元素。

Example:

// In HTML head, include a link to the NavigationHelpButton.css stylesheet,
// and in the body, include: <div id="navigationHelpButtonContainer"></div>

const navigationHelpButton = new Cesium.NavigationHelpButton({
    container : 'navigationHelpButtonContainer'
});