@Test
public void testToString() {

  SequentialProtocolProducer sequentialProtocolProducer =
      new SequentialProtocolProducer(
          Collections.singletonList(
              new SingleProtocolProducer<>(new DummyBooleanNotProtocol(null))));
  String toString = sequentialProtocolProducer.toString();
  Assert.assertThat(toString, StringContains.containsString("SequentialProtocolProducer"));
  Assert.assertThat(toString, StringContains.containsString("SingleProtocolProducer"));
  Assert.assertThat(toString, StringContains.containsString("DummyBooleanNotProtocol"));
  Assert.assertThat(sequentialProtocolProducer.toString(), Is.is(toString));
}