@Override
    public String toString() {
        return toString("");
    }
@Test
    public void shouldRecursivelyPrintChildren() {
        topology.addSource("source", "t")
                .addProcessor("processor", mockProcessorSupplier, "source")
                .addProcessor("child-one", mockProcessorSupplier, "processor")
                .addProcessor("child-one-one", mockProcessorSupplier, "child-one")
                .addProcessor("child-two", mockProcessorSupplier, "processor")
                .addProcessor("child-two-one", mockProcessorSupplier, "child-two");

        final String result = topology.getInternalBuilder().buildTopology().toString();
        assertThat(result, containsString("child-one:\n\t\tchildren:\t[child-one-one]"));
        assertThat(result, containsString("child-two:\n\t\tchildren:\t[child-two-one]"));
    }