code: func (resp *Response) WriteHeader(defaultStatusCode int, defaultContentType string) {
  	if resp.ContentType == "" {
  		resp.ContentType = defaultContentType
  	}
  	resp.Out.internalHeader.Set("Content-Type", resp.ContentType)
  	if resp.Status == 0 {
  		resp.Status = defaultStatusCode
  	}
  	resp.SetStatus(resp.Status)
  }
docs: // WriteHeader writes the header (for now, just the status code).
  // The status may be set directly by the application (c.Response.Status = 501).
  // If it isn't, then fall back to the provided status code.