override fun writeTo(sink: BufferedSink) {
    writeOrCountBytes(sink, false)
  }

  /**
   * Either writes this request to [sink] or measures its content length. We have one method do
   * double-duty to make sure the counting and content are consistent, particularly when it comes
   * to awkward operations like measuring the encoded length of header strings, or the
   * length-in-digits of an encoded integer.
   */