*/
  @Throws(IOException::class)
  fun processNextFrame() {
    readHeader()
    if (isControlFrame) {
      readControlFrame()
    } else {
      readMessageFrame()
    }
  }

  @Throws(IOException::class, ProtocolException::class)
  private fun readHeader() {
    if (closed) throw IOException("closed")

    // Disable the timeout to read the first byte of a new frame.

    if (result == null) {
      result = readHeader()
      peekedHeader = result
    }

    if (result.isEndOfData) return null

    return result
  }

  /**
   * Consume the next header in the stream and return it. If there is no header to read because we
   * have reached a limit, this returns [END_OF_DATA].
   */
  internal fun readHeader(): DerHeader {
    require(peekedHeader == null)

			return nil, err
		}
		if _, err := tryReadFull(tr.r, tr.blk[:tr.pad]); err != nil {
			return nil, err
		}
		tr.pad = 0

		hdr, rawHdr, err := tr.readHeader()
		if err != nil {
			return nil, err
		}
		if err := tr.handleRegularFile(hdr); err != nil {
			return nil, err
		}
		format.mayOnlyBe(hdr.Format)

		// Check for PAX/GNU special headers and files.

        .writeByte(0b11111111)
        .writeByte(0b11111111)
        .writeByte(0b11111111)
        .writeByte(0b11111111)

    val derReader = DerReader(buffer)

    val header = derReader.readHeader()
    assertThat(header.length).isEqualTo(Long.MAX_VALUE)
  }

  @Test fun `decode length overflowing Long`() {
    val buffer =
      Buffer()
        .writeByte(0b00000010)