original_string: public static function create_username($consumerkey, $ltiuserid) {
          if (!empty($ltiuserid) && !empty($consumerkey)) {
              $userkey = $consumerkey . ':' . $ltiuserid;
          } else {
              $userkey = false;
          }
  
          return 'enrol_lti' . sha1($consumerkey . '::' . $userkey);
      }
code: public static function create_username($consumerkey, $ltiuserid) {
          if (!empty($ltiuserid) && !empty($consumerkey)) {
              $userkey = $consumerkey . ':' . $ltiuserid;
          } else {
              $userkey = false;
          }
  
          return 'enrol_lti' . sha1($consumerkey . '::' . $userkey);
      }
code_tokens: public static function create_username ( $ consumerkey , $ ltiuserid ) { if ( ! empty ( $ ltiuserid ) && ! empty ( $ consumerkey ) ) { $ userkey = $ consumerkey . ':' . $ ltiuserid ; } else { $ userkey = false ; } return 'enrol_lti' . sha1 ( $ consumerkey . '::' . $ userkey ) ; }
docstring: Creates a unique username.
  
  @param string $consumerkey Consumer key
  @param string $ltiuserid External tool user id
  @return string The new username
docstring_tokens: Creates a unique username .