MediaType mediaType = addKnownType(new MediaType(type, subtype, UTF_8_CONSTANT_PARAMETERS));
    mediaType.parsedCharset = Optional.of(UTF_8);
    return mediaType;
  }

  @CanIgnoreReturnValue
  private static MediaType addKnownType(MediaType mediaType) {
    knownTypes.put(mediaType, mediaType);
    return mediaType;
  }

  /*
   * The following constants are grouped by their type and ordered alphabetically by the constant

    MediaType mediaType = addKnownType(new MediaType(type, subtype, UTF_8_CONSTANT_PARAMETERS));
    mediaType.parsedCharset = Optional.of(UTF_8);
    return mediaType;
  }

  @CanIgnoreReturnValue
  private static MediaType addKnownType(MediaType mediaType) {
    knownTypes.put(mediaType, mediaType);
    return mediaType;
  }

  /*
   * The following constants are grouped by their type and ordered alphabetically by the constant

   * Content-Type header.
   */
  override fun toString(): String = mediaType

  override fun equals(other: Any?): Boolean = other is MediaType && other.mediaType == mediaType

  override fun hashCode(): Int = mediaType.hashCode()

  companion object {
    private const val TOKEN = "([a-zA-Z0-9-!#$%&'*+.^_`{|}~]+)"
    private const val QUOTED = "\"([^\"]*)\""

     * @param mediaType the media type for the content builder
     * @return an OutputStream containing the built content, or an empty ByteArrayOutputStream if an error occurs
     */
    public static OutputStream getXContentBuilderOutputStream(final XContentBuilderCallback func, final MediaType mediaType) {
        try (final XContentBuilder builder = func.apply(mediaType.contentBuilder(), ToXContent.EMPTY_PARAMS)) {

	public static final fun create (Lokhttp3/MediaType;Lokio/ByteString;)Lokhttp3/RequestBody;
	public static final fun create (Lokhttp3/MediaType;[B)Lokhttp3/RequestBody;
	public static final fun create (Lokhttp3/MediaType;[BI)Lokhttp3/RequestBody;
	public static final fun create (Lokhttp3/MediaType;[BII)Lokhttp3/RequestBody;

    @JvmName("create")
    fun String.toRequestBody(contentType: MediaType? = null): RequestBody {
      val (charset, finalContentType) = contentType.chooseCharset()
      val bytes = toByteArray(charset)
      return bytes.toRequestBody(finalContentType, 0, bytes.size)
    }

    @JvmStatic
    @JvmName("create")
    fun ByteString.toRequestBody(contentType: MediaType? = null): RequestBody =
      object : RequestBody() {

import okio.Source
import okio.buffer

class ResponseBodyTest {
  @Test
  fun sourceEmpty() {
    val mediaType = if (null == null) null else "any/thing; charset=${null}".toMediaType()
    val body = "".decodeHex().toResponseBody(mediaType)
    val source = body.source()
    assertThat(source.exhausted()).isTrue()
    assertThat(source.readUtf8()).isEqualTo("")
  }

  @Test
  fun sourceClosesUnderlyingSource() {

  }

  @Test
  fun mediaType() {
    val mediaType: MediaType = "".toMediaType()
    val defaultCharset: Charset? = mediaType.charset()
    val charset: Charset? = mediaType.charset(Charsets.UTF_8)
    val type: String = mediaType.type
    val subtype: String = mediaType.subtype
    val parse: MediaType? = "".toMediaTypeOrNull()
  }

  @Test
  fun mockResponse() {

        MediaType.parse("text/plain; a=1; a=2").withParameter("a", "3"));
    assertEquals(
        MediaType.parse("text/plain; a=1; a=2; b=3"),
        MediaType.parse("text/plain; a=1; a=2").withParameter("b", "3"));
  }

  public void testWithParameter_invalidAttribute() {
    MediaType mediaType = MediaType.parse("text/plain");

    @JvmName("create")
    fun ByteArray.toResponseBody(contentType: MediaType? = null): ResponseBody =
      Buffer()
        .write(this)
        .asResponseBody(contentType, size.toLong())

    /** Returns a new response body that transmits this byte string. */
    @JvmStatic
    @JvmName("create")
    fun ByteString.toResponseBody(contentType: MediaType? = null): ResponseBody =
      Buffer()
        .write(this)