code: function indexOfHistoryByPageId(pageId) {
  	if (pageId.indexOf("?") !== -1) {
  		pageId = pageId.substring(0, pageId.indexOf("?"));
  	}
  
  	let index = -1;
  	for (let i = 0, len = this.getHistoryLength(); i < len; i++) {
  		if (this.getPageByIndex(i).getPageId() === pageId) {
  			index = i;
  			break;
  		}
  	}
  	return index;
  }
docs: history中是否有pageId开头的page对象
  @access private
  @param {string} pageId
  @return {number}