### Question:
CircusTrainCopyListing extends SimpleCopyListing { static void setAsCopyListingClass(Configuration conf) { conf.setClass(CONF_LABEL_COPY_LISTING_CLASS, CircusTrainCopyListing.class, CopyListing.class); } CircusTrainCopyListing(Configuration configuration, Credentials credentials); @Override void doBuildListing(Path pathToListFile, DistCpOptions options);  }### Answer:
@Test public void copyListingClass() { CircusTrainCopyListing.setAsCopyListingClass(conf); assertThat(conf.get(DistCpConstants.CONF_LABEL_COPY_LISTING_CLASS), is(CircusTrainCopyListing.class.getName())); }