def test_c(self):
"""Test the single zip file is returned."""
retriever = ZipFileNameRetriever()
retriever.retrieve_file_names = (lambda: ['hello.zip'])
file_names = retriever.retrieve()
self.assertEqual(['hello.zip'], file_names)
def test_b(self):
"""Test no files are returned when there are no zip files present."""
retriever = ZipFileNameRetriever()
retriever.retrieve_file_names = (lambda: ['hello.txt'])
file_names = retriever.retrieve()
self.assertEqual([], file_names)