import com.google.common.collect.ImmutableSet;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import org.jspecify.annotations.NullUnmarked;

/**
 * A byte sink for testing that has configurable behavior.
 *
 * @author Colin Decker
 */
@NullUnmarked
public class TestByteSink extends ByteSink implements TestStreamSupplier {

import java.io.FilterWriter;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.Writer;
import org.jspecify.annotations.NullUnmarked;

/**
 * A char sink for testing that has configurable behavior.
 *
 * @author Colin Decker
 */
@NullUnmarked
public class TestCharSink extends CharSink implements TestStreamSupplier {

  private final TestByteSink byteSink;

    ) = error("unsupported")

    override fun take() = error("unsupported")

    override fun remainingCapacity() = error("unsupported")

    override fun drainTo(sink: MutableCollection<in T>) = error("unsupported")

    override fun drainTo(
      sink: MutableCollection<in T>,
      maxElements: Int,
    ) = error("unsupported")
  }

              override fun contentLength(): Long = postBytes.size.toLong()

              override fun writeTo(sink: BufferedSink) {
                sink.write(postBytes) // push bytes into the stream's buffer
                sink.flush() // Http2Connection.writeData subject to write window
                sink.close() // Http2Connection.writeData empty frame
              }
            },
        ),
      )

  private class CountingSource(
    source: Source,
  ) : ForwardingSource(source) {
    var bytesRead = 0L

    override fun read(
      sink: Buffer,
      byteCount: Long,
    ): Long {
      val result = delegate.read(sink, byteCount)
      if (result == -1L) return -1L
      bytesRead += result
      return result
    }
  }

) : ResponseBody(),
  Source {
  override fun contentType() = mediaType

  override fun contentLength() = contentLength

  override fun source() = buffer()

  override fun read(
    sink: Buffer,
    byteCount: Long,
  ): Long =
    throw IllegalStateException(
      """
      |Unreadable ResponseBody! These Response objects have bodies that are stripped:
      | * Response.cacheResponse

HSPLokio/AsyncTimeout$Watchdog;-><init>()V
HSPLokio/AsyncTimeout$Watchdog;->run()V
HSPLokio/AsyncTimeout$sink$1;-><init>(Lokio/AsyncTimeout;Lokio/Sink;)V
HSPLokio/AsyncTimeout$sink$1;->close()V
HSPLokio/AsyncTimeout$sink$1;->flush()V
HSPLokio/AsyncTimeout$sink$1;->write(Lokio/Buffer;J)V
HSPLokio/AsyncTimeout$source$1;-><init>(Lokio/AsyncTimeout;Lokio/Source;)V
HSPLokio/AsyncTimeout$source$1;->close()V

    return client.newCall(request).execute()
  }

  private fun writeFile(
    directory: Path,
    file: String,
    content: String,
  ) {
    val sink = fileSystem.sink(directory.div(file)).buffer()
    sink.writeUtf8(content)
    sink.close()
  }

  /**
   * @param delta the offset from the current date to use. Negative values yield dates in the past;
   * positive values yield dates in the future.

          url = server.url("/"),
          body =
            object : ForwardingRequestBody(transferKind.newRequestBody("def")) {
              override fun writeTo(sink: BufferedSink) {
                sinkReference.set(sink)
                super.writeTo(sink)
              }
            },
        ),
      )
    assertThat(readAscii(response.body.byteStream(), Int.MAX_VALUE))
      .isEqualTo("abc")

      @Override public long contentLength() {
        return -1; // We don't know the compressed length in advance!
      }

      @Override public void writeTo(BufferedSink sink) throws IOException {
        BufferedSink gzipSink = Okio.buffer(new GzipSink(sink));
        body.writeTo(gzipSink);
        gzipSink.close();
      }
    };
  }
}
```

### Rewriting Responses