/** * @param int $flags * @return array|string */ public function build($flags = 0) { $lines = []; if ($flags & self::BUILD_STATUS && StatusCode::message($this->statusCode)) { $lines[] = 'HTTP/' . $this->version . ' ' . $this->statusCode . ' ' . StatusCode::message($this->statusCode); } foreach ($this->fields as $field => $value) { $lines[] = $field . ': ' . $value; } if ($flags & self::BUILD_FIELDS) { return implode("\r\n", $lines); } return $lines; }