@Before @SuppressWarnings("unchecked") public void setUp() throws IOException { String inputFile1 = tmpDir.copyResourceFileName("set1.txt"); String inputFile2 = tmpDir.copyResourceFileName("set2.txt"); if (pipelineClass == null) { pipeline = MemPipeline.getInstance(); } else { pipeline = new MRPipeline(pipelineClass, tmpDir.getDefaultConfiguration()); } PCollection<String> firstCollection = pipeline.read(At.textFile(inputFile1, typeFamily.strings())); PCollection<String> secondCollection = pipeline.read(At.textFile(inputFile2, typeFamily.strings())); LOG.info( "Test fixture: [" + pipeline.getClass().getSimpleName() + " : " + typeFamily.getClass().getSimpleName() + "] First: " + Lists.newArrayList(firstCollection.materialize().iterator()) + ", Second: " + Lists.newArrayList(secondCollection.materialize().iterator())); union = secondCollection.union(firstCollection); }