// send header info
relay.sendServerResponse(clientAddr, sourcesResp, timeout);
TestUtil.sleep(1000);
// when write data arrives from the server - we want to simulate/throw WriteTimeoutException
mock.enableThrowWTOException(true);
// send data
relay.sendServerResponse(clientAddr, new DefaultHttpChunk(streamResPrefix), timeout);
relay.sendServerResponse(clientAddr, HttpChunk.LAST_CHUNK, timeout);