*  New: Make the content-type header optional for request bodies.
 *  New: `Response.isSuccessful()` is a convenient API to check response codes.
 *  New: The response body can now be read outside of the callback. Response
    bodies must always be closed, otherwise they will leak connections!
 *  New: APIs to create multipart request bodies (`MultipartBuilder`) and form
    encoding bodies (`FormEncodingBuilder`).

## Version 2.0.0-RC1

    than 63 characters between dots), and empty labels.
 *  New: Don't include the `Content-Length` header in multipart bodies. Servers must delimit
    OkHttp's request bodies using the boundary only. (This change makes OkHttp more consistent with
    browsers and other HTTP clients.)
 *  New: Drop the `tunnelProxy` argument in `MockWebServer.useHttps()`. This change only impacts

      if (closed) return
      closed = true
      detachTimeout(timeout)
      state = STATE_READ_RESPONSE_HEADERS
    }
  }

  /**
   * An HTTP body with alternating chunk sizes and chunk bodies. It is the caller's responsibility
   * to buffer chunks; typically by using a buffered sink with this sink.
   */
  private inner class ChunkedSink : Sink {
    private val timeout = ForwardingTimeout(socket.sink.timeout())

          sink.writeUtf8("def")
        } catch (e: InterruptedException) {
          throw InterruptedIOException()
        }
      }
    }

  companion object {
    /** A large response body. Smaller bodies might successfully read after the socket is closed!  */
    private val BIG_ENOUGH_BODY = repeat('a', 64 * 1024)
  }

       * Content-Type: plain/text
       * Content-Length: 6
       * <-- END HTTP
       * ```
       */
      HEADERS,

      /**
       * Logs request and response lines and their respective headers and bodies (if present).
       *
       * Example:
       * ```
       * --> POST /greeting http/1.1
       * Host: example.com
       * Content-Type: plain/text
       * Content-Length: 3
       *
       * Hi?

  }

  /**
   * Regression test for an edge case where closing response body in the HTTP engine doesn't release
   * the corresponding stream allocation. This test keeps those response bodies alive and reads
   * them after the redirect has completed. This forces a connection to not be reused where it would
   * be otherwise.
   *
   *
   * This test leaks a response body by not closing it.
   *

 * request body start and end events occur within the response header events. Similarly,
 * [duplex calls][RequestBody.isDuplex] interleave the request and response bodies.
 *
 * Since connections may be reused, the proxy selection, DNS, and connect events may not be present
 * for a call. In future releases of OkHttp these events may also occur concurrently to permit

   * registry suffix is one under which Internet users can directly register names via a domain name
   * registrar, and have such registrations lawfully protected by internet-governing bodies such as
   * ICANN. Examples of registry suffixes include {@code com}, {@code co.uk}, and {@code
   * pvt.k12.wy.us}. Examples of domain names that are <i>not</i> registry suffixes include {@code

        }
      }
    ```

### Posting a multipart request ([.kt][PostMultipartKotlin], [.java][PostMultipartJava])

    private final File file;
    private final ImmutableSet<FileWriteMode> modes;

    private FileByteSink(File file, FileWriteMode... modes) {
      this.file = checkNotNull(file);
      this.modes = ImmutableSet.copyOf(modes);
    }

    @Override
    public FileOutputStream openStream() throws IOException {
      return new FileOutputStream(file, modes.contains(APPEND));
    }

    @Override