// Read the header.
      val header = Buffer()
      fileOperator.read(0, header, FILE_HEADER_SIZE)
      val prefix = header.readByteString(PREFIX_CLEAN.size.toLong())
      if (prefix != PREFIX_CLEAN) throw IOException("unreadable cache file")
      val upstreamSize = header.readLong()
      val metadataSize = header.readLong()

      // Read the metadata.

    The upcoming Android Studio runs in a JVM but has classes from Android and that confused OkHttp!

 *  Fix: Include the header `Accept: text/event-stream` for SSE calls. This header is not added if
    the request already contains an `Accept` header.

 *  Fix: Don't crash with a `NullPointerException` if a server sends a close while we're sending a
    ping. OkHttp had a race condition bug.

    val derReader = DerReader(buffer)

    derReader.read("test") { header ->
      assertThat(header.tag).isEqualTo(2L)
      assertThat(header.tagClass).isEqualTo(DerHeader.TAG_CLASS_CONTEXT_SPECIFIC)
      assertThat(header.length).isEqualTo(7L)

      derReader.read("test") { header ->
        assertThat(header.tag).isEqualTo(3L)
        assertThat(header.tagClass).isEqualTo(DerHeader.TAG_CLASS_APPLICATION)

            override fun close() {
              closed.set(true)
              super.close()
            }
          }.buffer()
        }
      }
    val reader = body.charStream()
    assertThat(reader.read()).isEqualTo('h'.code)
    reader.close()
    assertThat(closed.get()).isTrue()
  }

  @Test
  fun sourceSeesBom() {
    val body = "efbbbf68656c6c6f".decodeHex().toResponseBody()

  for (i in 0 until length) {
    val c = this[i]
    // The WHATWG Host parsing rules accepts some character codes which are invalid by
    // definition for OkHttp's host header checks (and the WHATWG Host syntax definition). Here
    // we rule out characters that would cause problems in host headers.
    if (c <= '\u001f' || c >= '\u007f') {
      return true
    }

          (length0 and 0b0111_1111).toLong()
        }
      }

    // Note that this may be be an encoded "end of data" header.
    return DerHeader(tagClass, tag, constructed, length)
  }

  /**
   * Consume a header and execute [block], which should consume the entire value described by the
   * header. It is an error to not consume a full value in [block].
   */
  internal inline fun <T> read(
    name: String?,

    ) {
      for (pushPromise in promises) {
        val pushedHeaders = mutableListOf<Header>()
        pushedHeaders.add(Header(Header.TARGET_AUTHORITY, url(pushPromise.path).host))
        pushedHeaders.add(Header(Header.TARGET_METHOD, pushPromise.method))
        pushedHeaders.add(Header(Header.TARGET_PATH, pushPromise.path))
        val pushPromiseHeaders = pushPromise.headers

     * set, the max age is preferred.
     */
    private var expires: Date? = null

    /**
     * Extension header set by OkHttp specifying the timestamp when the cached HTTP request was
     * first initiated.
     */
    private var sentRequestMillis = 0L

    /**
     * Extension header set by OkHttp specifying the timestamp when the cached HTTP response was
     * first received.
     */

    headers: Headers,
    inFinished: Boolean,
  ) {
    lock.assertNotHeld()

    val open: Boolean
    this.withLock {
      if (!hasResponseHeaders ||
        headers[Header.RESPONSE_STATUS_UTF8] != null ||
        headers[Header.TARGET_METHOD_UTF8] != null
      ) {
        hasResponseHeaders = true
        headersQueue += headers
      } else {
        this.source.trailers = headers
      }

      encodings[codePoint] = encoding
    }
  }

  fun nonPrintableAscii(encoding: Encoding) =
    apply {
      encodings[ 0x0] = encoding // Null character
      encodings[ 0x1] = encoding // Start of Header
      encodings[ 0x2] = encoding // Start of Text
      encodings[ 0x3] = encoding // End of Text
      encodings[ 0x4] = encoding // End of Transmission
      encodings[ 0x5] = encoding // Enquiry