def METHOD_NAME(self):
    super().METHOD_NAME()
    self.useFixture(fixture_setup.FakeTerminal())
    self.fake_logger = fixtures.FakeLogger(level=logging.DEBUG)
    self.useFixture(self.fake_logger)
    self.workdir = self.useFixture(fixtures.TempDir()).path
    self.source_file = os.path.join(self.workdir, "source.snap")
    self.target_file = os.path.join(self.workdir, "target.snap")
    with open(self.source_file, "wb") as f:
        f.write(b"This is the source file.")
    with open(self.target_file, "wb") as f:
        f.write(b"This is the target file.")