OkHttp may add headers that are absent from the original request, including `Content-Length`, `Transfer-Encoding`, `User-Agent`, `Host`, `Connection`, and `Content-Type`. It will add an `Accept-Encoding` header for transparent response compression unless the header is already present. If you’ve got cookies, OkHttp will add a `Cookie` header with them.

OkHttp Brotli Implementation
============================

This module is an implementation of [Brotli][1] compression.
It enables Brotli support in addition to tranparent Gzip support,
provided Accept-Encoding is not set previously.  Modern web servers
must choose to return Brotli responses.  n.b. It is not used for
sending requests.

```java
OkHttpClient client = new OkHttpClient.Builder()
  .addInterceptor(BrotliInterceptor.INSTANCE)
  .build();

  private fun skipName(source: Buffer) {
    // 0 - 63 bytes
    var length = source.readByte().toInt()

    if (length < 0) {
      // compressed name pointer, first two bits are 1
      // drop second byte of compression offset
      source.skip(1)
    } else {
      while (length > 0) {
        // skip each part of the domain name
        source.skip(length.toLong())
        length = source.readByte().toInt()
      }

/**
 * Transparent Compressed response support.
 *
 * The algorithm map will be turned into a heading such as "Accept-Encoding: br, gzip"
 *
 * If [algorithms] is empty this interceptor has no effect. To disable compression set
 * a specific "Accept-Encoding: identity" or similar.
 *
 * See https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/Accept-Encoding
 */
open class CompressionInterceptor(

        assertEquals(0, result.length);
    }

    public void test_gzipCompress_and_gzipDecompress() {
        String testData =
                "This is test data for compression that should be long enough to actually compress effectively when using gzip compression algorithm";
        byte[] originalBytes = testData.getBytes();

        byte[] compressed = searchHelper.gzipCompress(originalBytes);

Content-Type: text/plain
Content-Length: 1759
Connection: keep-alive
```

The network requests also contain more data, such as the `Accept-Encoding: gzip` header added by OkHttp to advertise support for response compression. The network interceptor's `Chain` has a non-null `Connection` that can be used to interrogate the IP address and TLS configuration that were used to connect to the webserver.

   * Variable-length quantity special cases strings which are longer than 127 bytes.  Values such as
   * cookies can be 4KiB, and should be possible to send.
   *
   *  http://tools.ietf.org/html/draft-ietf-httpbis-header-compression-12#section-5.2
   */
  @Test
  fun largeHeaderValue() {
    val value = CharArray(4096)
    Arrays.fill(value, '!')
    val headerBlock = headerEntries("cookie", String(value))

    assertFailsWith<Exception> {
      inflater.inflate("f240e30300".decodeHex())
    }
  }

  /**
   * Test for an [EOFException] caused by mishandling of fragmented buffers in web socket
   * compression. https://github.com/square/okhttp/issues/5965
   */
  @Test fun `inflate golden value in buffer that has been fragmented`() {
    val inflater = MessageInflater(false)

  val random: Random,
  private val perMessageDeflate: Boolean,
  private val noContextTakeover: Boolean,
  private val minimumDeflateSize: Long,
) : Closeable {
  /** This holds outbound data for compression and masking. */
  private val messageBuffer = Buffer()

  /** The [Buffer] of [sink]. Write to this and then flush/emit [sink]. */
  private val sinkBuffer: Buffer = sink.buffer
  private var writerClosed = false

   * addresses, the output follows <a href="http://tools.ietf.org/html/rfc5952">RFC 5952</a> section
   * 4. The main difference is that this method uses "::" for zero compression, while Java's version
   * uses the uncompressed form (except on Android, where the zero compression is also done). The
   * other difference is that this method outputs any scope ID in the format that it was provided at