code: func (body *Body) Buffer() *bytes.Buffer {
  	var b bytes.Buffer
  	if body.Reader == nil {
  		return &b
  	}
  
  	b.ReadFrom(body.Reader)
  	_, err := body.Reader.(io.Seeker).Seek(0, 0)
  	if err != nil {
  		log.Fatal(err)
  	}
  	return &b
  }
docs: // Buffer creates a  byte.Buffer copy from a io.Reader resets read on reader to 0,0