code: public function setStatusCode($value, $text = null)
      {
          if ($value === null) {
              $value = 200;
          }
          $this->_statusCode = (int) $value;
          if ($this->getIsInvalid()) {
              throw new InvalidArgumentException("The HTTP status code is invalid: $value");
          }
          if ($text === null) {
              $this->statusText = isset(static::$httpStatuses[$this->_statusCode]) ? static::$httpStatuses[$this->_statusCode] : '';
          } else {
              $this->statusText = $text;
          }
  
          return $this;
      }
docs: Sets the response status code.
  This method will set the corresponding status text if `$text` is null.
  @param int $value the status code
  @param string $text the status text. If not set, it will be set automatically based on the status code.
  @throws InvalidArgumentException if the status code is invalid.
  @return $this the response object itself