/** Lookup table for valid frame types. */
  private val FRAME_NAMES =
    arrayOf(
      "DATA",
      "HEADERS",
      "PRIORITY",
      "RST_STREAM",
      "SETTINGS",
      "PUSH_PROMISE",
      "PING",
      "GOAWAY",
      "WINDOW_UPDATE",
      "CONTINUATION",
    )

  /**
   * Lookup table for valid flags for DATA, HEADERS, CONTINUATION. Invalid combinations are

      if (associatedStreamId == 0) {
        writer.headers(outFinished, streamId, requestHeaders)
      } else {
        require(!client) { "client streams shouldn't have associated stream IDs" }
        // HTTP/2 has a PUSH_PROMISE frame.
        writer.pushPromise(associatedStreamId, streamId, requestHeaders)
      }
    }

    if (flushHeaders) {
      writer.flush()
    }

    return stream
  }