public long contentLength() throws IOException {
      return delegate.contentLength();
    }

    @Override
    public void writeTo(BufferedSink sink) throws IOException {
      BufferedSink bufferedSink = Okio.buffer(sink(sink));
      delegate.writeTo(bufferedSink);
      bufferedSink.flush();
    }

    public Sink sink(Sink sink) {
      return new ForwardingSink(sink) {
        private long totalBytesWritten = 0L;

              completed = true
              progressListener.update(totalBytesWritten, contentLength(), completed)
            }
          }
        }

      val bufferedSink = forwardingSink.buffer()
      delegate.writeTo(bufferedSink)
      bufferedSink.flush()
    }
  }

  fun interface ProgressListener {
    fun update(
      bytesWritten: Long,
      contentLength: Long,
      done: Boolean,
    )

import okhttp3.Response
import okhttp3.mockwebserver.MockResponse
import okhttp3.mockwebserver.MockWebServer
import okhttp3.mockwebserver.SocketPolicy
import okhttp3.testing.PlatformRule
import okio.Buffer
import okio.BufferedSink
import org.junit.jupiter.api.AfterEach
import org.junit.jupiter.api.BeforeEach
import org.junit.jupiter.api.Tag
import org.junit.jupiter.api.Test
import org.junit.jupiter.api.extension.RegisterExtension

            return delegate.contentLength();
          }

          @Override public void writeTo(BufferedSink sink) throws IOException {
            BufferedSink bufferedSink = Okio.buffer(sink(sink));
            delegate.writeTo(bufferedSink);
            bufferedSink.flush();
          }

          public Sink sink(Sink sink) {
            return new ForwardingSink(sink) {