### Question:
TcpServerFactory { public TcpServer createTcpServer(final int port) { final Map<String, ? extends DataHandler> dataHandlersMap = dataHandlersLoader.dataHandlers(); final String dataHandlersList = dataHandlersMap.keySet() .stream() .map(key -> String.format("\t- %s", key)) .collect(joining("\n")); if (dataHandlersMap.isEmpty()) { logger.warn("No Data Handlers!"); } else { logger.info("Data Handlers ({}):\n{}", dataHandlersMap.size(), dataHandlersList); } serverBuilder.withDataHandlers(dataHandlersMap.values()); serverBuilder.withPort(port); final TcpServer server = serverBuilder.build(); logger.info("Server Started (:{})", server.getPort()); return server; } TcpServerFactory(final TcpServerBuilder<? extends TcpServer> serverBuilder,
                            final DataHandlersLoader dataHandlersLoader); TcpServer createTcpServer(final int port);  }### Answer:
@Test public void testDataHandlersLoading() { final DefaultDataHandlersLoader dataHandlersLoader = new DefaultDataHandlersLoader(); final TcpServerFactory tcpServerFactory = new TcpServerFactory(new TestTcpServerBuilder(hasSize(TEST_MAPPINGS.size())), dataHandlersLoader); tcpServerFactory.createTcpServer(0); }