original_string: public function addHeader(string $key, string $value): Response
      {
          $this->headers->add($key, $value);
          return $this;
      }
code: public function addHeader(string $key, string $value): Response
      {
          $this->headers->add($key, $value);
          return $this;
      }
code_tokens: public function addHeader ( string $ key , string $ value ) : Response { $ this -> headers -> add ( $ key , $ value ) ; return $ this ; }
docstring: Add a header
  Allows for adding multiple headers with the same key
  
  @param string $key
  @param string $value
  @return \sndsgd\http\Response
docstring_tokens: Add a header Allows for adding multiple headers with the same key