You can set a custom body with a string, input stream or byte array. Also
add headers with a fluent builder API.

```java
MockResponse response = new MockResponse()
    .addHeader("Content-Type", "application/json; charset=utf-8")
    .addHeader("Cache-Control", "no-cache")
    .setBody("{}");
```

MockResponse can be used to simulate a slow network. This is useful for
testing timeouts and interactive testing.

```java

kotlinx-serialization-core = { module = "org.jetbrains.kotlinx:kotlinx-serialization-core", version.ref = "kotlinx-serialization" }
kotlinx-serialization-json = { module = "org.jetbrains.kotlinx:kotlinx-serialization-json", version.ref = "kotlinx-serialization" }
mockserver = { module = "org.testcontainers:mockserver", version.ref = "testcontainers" }

package okhttp3

import kotlinx.serialization.Serializable
import kotlinx.serialization.decodeFromString
import kotlinx.serialization.json.Json

/**
 * A test from the [Web Platform To ASCII](https://github.com/web-platform-tests/wpt/blob/master/url/resources/toascii.json).
 *
 * Each test is a line of the file `toascii.json`.
 */
@Serializable
class WebPlatformToAsciiData {
  var input: String? = null
  var output: String? = null

          @FromJson fun byteStringFromJson(json: String) = json.decodeHex()
        },
      )
      .add(KotlinJsonAdapterFactory())
      .build()
  private val STORY_JSON_ADAPTER = MOSHI.adapter(Story::class.java)

  private val fileSystem = FileSystem.SYSTEM

  private fun readStory(source: BufferedSource): Story {
    return STORY_JSON_ADAPTER.fromJson(source)!!
  }

  integrity sha512-LG4opVs2ANWZ1TJoKc937iMmNstM/d0ae1vNbnBvBhqCSezgVUOzcLCqbI5elV8Vy6WKwKjaqR+zO9VKirBBCA==

"@types/json-schema@*", "@types/json-schema@^7.0.8":
  version "7.0.11"
  resolved "https://registry.yarnpkg.com/@types/json-schema/-/json-schema-7.0.11.tgz#d421b6c527a3037f7c84433fd2c4229e016863d3"
  integrity sha512-wOuvG1SN4Us4rez+tylwwwCV1psiNVOkJeM3AUWUNWg/jDQY2+HE/444y5gc+jBmRqASOm2Oeh5c1axHobwRKQ==

----------------

This program posts data to a service. [Full source][post_example].

```java
public static final MediaType JSON = MediaType.get("application/json");

OkHttpClient client = new OkHttpClient();

String post(String url, String json) throws IOException {
  RequestBody body = RequestBody.create(json, JSON);
  Request request = new Request.Builder()
      .url(url)
      .post(body)
      .build();

  private val client = OkHttpClient()
  private val fileSystem = FakeFileSystem()
  val path = "test.json".toPath()

  fun run() {
    fileSystem.write(path) {
      writeUtf8("{}")
    }

    val request =
      Request.Builder()
        .url("https://httpbin.org/anything")
        .put(path.asRequestBody(fileSystem, MEDIA_TYPE_JSON))
        .build()

    client.newCall(request).execute().use { response ->

import okhttp3.internal.format
import okio.Buffer
import okio.BufferedSource

/**
 * A test from the [Web Platform URL test suite](https://github.com/web-platform-tests/wpt/blob/master/url/resources/urltestdata.json).
 *
 * Each test is a line of the file `urltestdata.txt`. The format is informally specified by its
 * JavaScript parser `urltestparser.js` with which this class attempts to be compatible.
 *

 * [Hunter](https://github.com/Leaking/Hunter): Configure all OkHttpClients centrally.
 * ⬜️ [Moshi](https://github.com/square/moshi): A modern JSON library for Android and Java.
 * [Ok2Curl](https://github.com/mrmike/Ok2Curl): Convert OkHttp requests into curl logs.
 * [OkHttp AWS Signer](https://github.com/babbel/okhttp-aws-signer): AWS V4 signing algorithm for OkHttp requests

    assertThat(bodyToHex(body), "Retransmit body").isEqualTo("616263")
  }

  /** Common verbs used for apis such as GitHub, AWS, and Google Cloud.  */
  @Test
  fun crudVerbs() {
    val contentType = "application/json".toMediaType()
    val body = "{}".toRequestBody(contentType)

    val get = Request.Builder().url("http://localhost/api").get().build()
    assertThat(get.method).isEqualTo("GET")
    assertThat(get.body).isNull()