code: public CrawlElement click(String tagName) {
  		checkNotRead();
  		Preconditions.checkNotNull(tagName, "Tag name cannot be null");
  		CrawlElement crawlTag = new CrawlElement(EventType.click,
  				tagName.toUpperCase());
  		crawlElements.add(crawlTag);
  		return crawlTag;
  	}
docs: Set of HTML elements Crawljax will click during crawling For example 1)
  &gt;a.../&lt; 2) &lt;div/&gt; click("a") will only include 1 if clickOnce
  is true (default). This set can be restricted by
  {@link #dontClick(String)}.
  
  @param tagName the tag name of the elements to be included
  @return this CrawlElement