* to call getCopy and removeAllNodes only with a true K, then we could check containsKey first.
     * But that check wouldn't eliminate the warnings.)
     */
    @SuppressWarnings({"unchecked", "nullness"})
    K castKey = (K) key;
    List<V> oldValues = getCopy(castKey);
    removeAllNodes(castKey);
    return oldValues;
  }

  @Override

  val result = mockwebserver3.MockResponse.Builder()
  val copyFromWebSocketListener = webSocketListener
  if (copyFromWebSocketListener != null) {
    result.webSocketUpgrade(copyFromWebSocketListener)
  }

  val body = getBody()
  if (body != null) result.body(body)

  for (pushPromise in pushPromises) {
    result.addPush(pushPromise.wrap())
  }

  result.settings(settings)
  result.status(status)
  result.headers(headers)

RecordedRequest request = server.takeRequest();
assertEquals("POST /v1/chat/send HTTP/1.1", request.getRequestLine());
assertEquals("application/json; charset=utf-8", request.getHeaders().get("Content-Type"));
assertEquals("{}", request.getBody().readUtf8());
```

### Kotlin
```kotlin
val request = server.takeRequest()
assertEquals("POST /v1/chat/send HTTP/1.1", request.requestLine)

    mockResponse = mockResponse.setHeader("", Any())
    mockResponse.headers = headersOf()
    mockResponse.trailers = headersOf()
    mockResponse = mockResponse.removeHeader("")
    var body: Buffer? = mockResponse.getBody()
    mockResponse = mockResponse.setBody(Buffer())
    mockResponse = mockResponse.setChunkedBody(Buffer(), 0)
    mockResponse = mockResponse.setChunkedBody("", 0)

  }

  @Test
  fun setBodyAdjustsHeaders() {
    val response = MockResponse().setBody("ABC")
    assertThat(headersToList(response)).containsExactly("Content-Length: 3")
    assertThat(response.getBody()!!.readUtf8()).isEqualTo("ABC")
  }

  @Test
  fun mockResponseAddHeader() {
    val response =
      MockResponse()
        .clearHeaders()
        .addHeader("Cookie: s=square")