original_string: public function getParam($index)
      {
          if (!isset($this->params[$index])) {
              throw new \InvalidArgumentException('Route parameter does not exist at specified index');
          }
  
          return $this->params[$index];
      }
code: public function getParam($index)
      {
          if (!isset($this->params[$index])) {
              throw new \InvalidArgumentException('Route parameter does not exist at specified index');
          }
  
          return $this->params[$index];
      }
code_tokens: public function getParam ( $ index ) { if ( ! isset ( $ this -> params [ $ index ] ) ) { throw new \ InvalidArgumentException ( 'Route parameter does not exist at specified index' ) ; } return $ this -> params [ $ index ] ; }
docstring: Get route parameter value
  @param  string                    $index Name of URL parameter
  @return string
  @throws \InvalidArgumentException        If route parameter does not exist at index
  @api
docstring_tokens: Get route parameter value