byte[] compressed = compressionService.compress(testData, CompressionService.COMPRESSION_LZ77);
        assertNotNull(compressed);
        assertTrue(compressed.length > 0);
        // Compressed size should typically be smaller (though not guaranteed for all data)

        byte[] decompressed = compressionService.decompress(compressed, CompressionService.COMPRESSION_LZ77);

     * @param algorithm the compression algorithm to use
     * @return the compressed data
     * @throws CIFSException if compression fails
     */
    byte[] compress(byte[] data, int offset, int length, int algorithm) throws CIFSException;

    /**
     * Decompresses data that was compressed with the specified algorithm.
     *
     * @param compressedData the compressed data
     * @param algorithm the compression algorithm that was used

    }

    /**
     * Decompresses GZIP-compressed data.
     *
     * @param compressed The GZIP-compressed data to decompress
     * @return Decompressed data
     * @throws IORuntimeException if decompression fails
     */
    protected byte[] gzipDecompress(final byte[] compressed) {
        try (final ByteArrayInputStream bis = new ByteArrayInputStream(compressed);

 */
package okhttp3

import okhttp3.ResponseBody.Companion.asResponseBody
import okhttp3.internal.http.promisesBody
import okio.BufferedSource
import okio.Source
import okio.buffer

/**
 * 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

        }
        return address;
    }

    /**
     * Compresses an IPv6 address string to its canonical compressed form.
     * For example, "0:0:0:0:0:0:0:1" becomes "::1"
     *
     * @param ipv6Address the IPv6 address string to compress
     * @return the compressed IPv6 address string
     */
    protected static String compressIPv6(final String ipv6Address) {

    callback.assertTextMessage("Hello")
  }

  @Test fun serverWithCompressionCompressedHelloTwoChunks() {
    data.write("418460b420bb92fced72".decodeHex()) // first 4 bytes of compressed 'Hello'
    data.write("80833851d9d4f156d9".decodeHex()) // last 3 bytes of compressed 'Hello'
    serverReaderWithCompression.processNextFrame()
    callback.assertTextMessage("Hello")
  }

  @Test fun clientTwoFrameHello() {

  @Test
  fun testNoDecompress() {
    val s = "hello not compressed world".encodeUtf8()

    val response = response("https://example.com/", s)

    val decompressed = zstdInterceptor.decompress(response)
    assertThat(decompressed.header("Content-Encoding")).isNull()

    val responseString = decompressed.body.string()
    assertThat(responseString).isEqualTo("hello not compressed world")
  }

  @Test
  fun testUnknownAlgorithm() {

Interceptors can be chained. Suppose you have both a compressing interceptor and a checksumming interceptor: you'll need to decide whether data is compressed and then checksummed, or checksummed and then compressed. OkHttp uses lists to track interceptors, and interceptors are called in order.

![Interceptors Diagram](../assets/images/******@****.***)

### Application Interceptors

@SuppressWarnings("serial") // uses writeReplace(), not default serialization
final class SingletonImmutableSet<E> extends ImmutableSet<E> {
  // We deliberately avoid caching the asList and hashCode here, to ensure that with
  // compressed oops, a SingletonImmutableSet packs all the way down to the optimal 16 bytes.

  final transient E element;

  SingletonImmutableSet(E element) {
    this.element = Preconditions.checkNotNull(element);
  }

            throw new CIFSException("Compressed data cannot be null");
        }
        return decompress(compressedData, 0, compressedData.length, algorithm);
    }

    @Override
    public byte[] decompress(byte[] compressedData, int offset, int length, int algorithm) throws CIFSException {
        if (compressedData == null) {
            throw new CIFSException("Compressed data cannot be null");
        }