}

  @Test
  fun stringWithDefaultCharsetAdded() {
    val contentType = "text/plain".toMediaType()
    val body = "\u0800".toRequestBody(contentType)
    assertThat(body.contentType()).isEqualTo("text/plain; charset=utf-8".toMediaType())
    assertThat(body.contentLength()).isEqualTo(3)
    assertThat(bodyToHex(body)).isEqualTo("e0a080")
  }

  @Test

    @JvmField
    val MIXED = "multipart/mixed".toMediaType()

    /**
     * The "multipart/alternative" type is syntactically identical to "multipart/mixed", but the
     * semantics are different. In particular, each of the body parts is an "alternative" version of
     * the same information.
     */
    @JvmField
    val ALTERNATIVE = "multipart/alternative".toMediaType()

    /**

import java.util.Arrays
import mockwebserver3.MockResponse
import mockwebserver3.MockWebServer
import mockwebserver3.junit5.StartStop
import okhttp3.HttpUrl
import okhttp3.MediaType.Companion.toMediaType
import okhttp3.OkHttpClient
import okhttp3.OkHttpClientTestRule
import okhttp3.Protocol
import okhttp3.Request
import okhttp3.RequestBody.Companion.toRequestBody
import okhttp3.Response

    val body = text.toResponseBody("text/plain; charset=unknown".toMediaType())
    assertThat(body.string()).isEqualTo(text)
  }

  companion object {
    @JvmOverloads
    fun body(
      hex: String,
      charset: String? = null,
    ): ResponseBody {
      val mediaType = if (charset == null) null else "any/thing; charset=$charset".toMediaType()
      return hex.decodeHex().toResponseBody(mediaType)
    }

    responseBody.close()
    responseBody = "".toResponseBody("".toMediaType())
    responseBody = "".toResponseBody(null)
    responseBody = ByteString.EMPTY.toResponseBody("".toMediaType())
    responseBody = ByteString.EMPTY.toResponseBody(null)
    responseBody = byteArrayOf(0, 1).toResponseBody("".toMediaType())
    responseBody = byteArrayOf(0, 1).toResponseBody(null)

import mockwebserver3.MockResponse
import mockwebserver3.MockWebServer
import mockwebserver3.SocketEffect.ShutdownConnection
import mockwebserver3.junit5.StartStop
import okhttp3.MediaType.Companion.toMediaType
import okhttp3.RequestBody.Companion.toRequestBody
import okhttp3.ResponseBody.Companion.toResponseBody
import okhttp3.TestUtil.assertSuppressed
import okio.Buffer
import okio.BufferedSink
import okio.ForwardingSink

import assertk.assertions.isEqualTo
import java.io.IOException
import java.nio.charset.StandardCharsets
import kotlin.test.assertFailsWith
import okhttp3.Headers.Companion.headersOf
import okhttp3.MediaType.Companion.toMediaType
import okhttp3.MediaType.Companion.toMediaTypeOrNull
import okhttp3.RequestBody.Companion.toRequestBody
import okio.Buffer
import okio.BufferedSink
import okio.utf8Size
import org.junit.jupiter.api.Test

import mockwebserver3.SocketEffect.CloseSocket
import mockwebserver3.SocketEffect.ShutdownConnection
import mockwebserver3.junit5.StartStop
import okhttp3.Headers.Companion.headersOf
import okhttp3.MediaType.Companion.toMediaType
import okhttp3.RequestBody.Companion.toRequestBody
import okhttp3.ResponseBody.Companion.toResponseBody
import okhttp3.internal.closeQuietly
import okhttp3.testing.PlatformRule
import okhttp3.tls.HandshakeCertificates

import assertk.assertions.isNull
import java.io.EOFException
import java.net.ProtocolException
import kotlin.test.assertFailsWith
import okhttp3.Headers.Companion.headersOf
import okhttp3.MediaType.Companion.toMediaType
import okhttp3.MediaType.Companion.toMediaTypeOrNull
import okhttp3.RequestBody.Companion.toRequestBody
import okhttp3.ResponseBody.Companion.toResponseBody
import okio.Buffer
import okio.BufferedSink

          println(response.body!!.string())
        }
      }

      companion object {
        val MEDIA_TYPE_MARKDOWN = "text/x-markdown; charset=utf-8".toMediaType()
      }
    ```
=== ":material-language-java: Java"
    ```java
      public static final MediaType MEDIA_TYPE_MARKDOWN
          = MediaType.parse("text/x-markdown; charset=utf-8");