original_string: public function getHeader($name)
      {
          $name = $this->normalizeHeaderName($name);
          if (isset($this->_environment[$name])) {
              return (array)$this->_environment[$name];
          }
  
          return [];
      }
code: public function getHeader($name)
      {
          $name = $this->normalizeHeaderName($name);
          if (isset($this->_environment[$name])) {
              return (array)$this->_environment[$name];
          }
  
          return [];
      }
code_tokens: public function getHeader ( $ name ) { $ name = $ this -> normalizeHeaderName ( $ name ) ; if ( isset ( $ this -> _environment [ $ name ] ) ) { return ( array ) $ this -> _environment [ $ name ] ; } return [ ] ; }
docstring: Get a single header from the request.
  
  Return the header value as an array. If the header
  is not present an empty array will be returned.
  
  @param string $name The header you want to get (case-insensitive)
  @return array An associative array of headers and their values.
  If the header doesn't exist, an empty array will be returned.
  @link http://www.php-fig.org/psr/psr-7/ This method is part of the PSR-7 server request interface.
docstring_tokens: Get a single header from the request .