code: protected boolean doStripRegexMatch(StringBuilder url, Matcher matcher) {
      	if(matcher != null && matcher.matches()) {
      		url.delete(matcher.start(1), matcher.end(1));
      		return true;
      	}
      	return false;
      }
docs: Run a regex against a StringBuilder, removing group 1 if it matches.
  
  Assumes the regex has a form that wants to strip elements of the passed
  string.  Assumes that if a match, group 1 should be removed
  @param url Url to search in.
  @param matcher Matcher whose form yields a group to remove
  @return true if the StringBuilder was modified