public void ShouldSendSync() { var sync = JsonStrings.CommandSyncOut(); var format = Substitute.For<IProtocolWriterFormat>(); format.Sync().Returns(sync); var writer = Substitute.For<IWriteNext>(); var reader = Substitute.For<IStormReader>(); var subjectUnderTest = new StandardSpoutWriter(writer, format, reader); subjectUnderTest.Sync(); writer.Received().Write(sync); }