code: public String getApiDocRoot(String className) {
  	if(apiDocMap.isEmpty())
  	    apiDocMap.put(Pattern.compile(".*"), DEFAULT_EXTERNAL_APIDOC);
  	
  	for (Map.Entry<Pattern, String> mapEntry : apiDocMap.entrySet()) {
  	    if (mapEntry.getKey().matcher(className).matches())
  		return mapEntry.getValue();
  	}
  	return null;
      }
docs: Returns the appropriate URL "root" for an external class name.  It will
  match the class name against the regular expressions specified in the
  <code>apiDocMap</code>; if a match is found, the associated URL
  will be returned.
  <p>
  <b>NOTE:</b> The match order of the match attempts is the one specified by the
  constructor of the api doc root, so it depends on the order of "-link" and "-apiDocMap"
  parameters.