protected function getHeaderValue($header_name, $headers) {
    foreach($headers as $key => $value) {
      if (strcasecmp($key, $header_name) === 0) {
        return $value;
      }
    }
    return null;
  }
protected function getHeaderValue($header_name, $headers) {
    foreach($headers as $key => $value) {
      if (strcasecmp($key, $header_name) === 0) {
        return $value;
      }
    }
    return null;
  }
protected function getHeaderValue ( $ header_name , $ headers ) { foreach ( $ headers as $ key => $ value ) { if ( strcasecmp ( $ key , $ header_name ) === 0 ) { return $ value ; } } return null ; }
Return the value of a header stored in an associative array, using a case
insensitive comparison on the header name.

@param $header_name string The name of the header to lookup.
@param $headers array Associative array of headers.

@return The value of the header if found, false otherwise.
Return the value of a header stored in an associative array using a case insensitive comparison on the header name .