@Test
public void send() throws Exception {

  underTest.connect();
  RemoteEndpoint.Basic basicRemote = mock(RemoteEndpoint.Basic.class);
  doReturn(basicRemote).when(session).getBasicRemote();
  underTest.send(new Cancel());
  verify(basicRemote).sendBinary(ByteBuffer.wrap("{\"type\":\"CANCEL\"}".getBytes()));
}