code: public function getParam($key, $default = null)
      {
          $param = parent::getParam($key, $default);
  
          if (is_string($param)) {
              return trim($param);
          }
  
          return $param;
      }
docs: Retrieve a parameter.
  
  Retrieves a parameter from the instance. Priority is in the order of
  userland parameters (see {@link setParam()}), $_GET, $_POST. If a
  parameter matching the $key is not found, null is returned.
  
  If the $key is an alias, the actual key aliased will be used.
  
  @param mixed $key
  @param mixed $default Default value to use if key not found
  @return mixed