def test_ensure_files_exist(self):
    'Test _ensure_files_exist raises exception with a non-existent\n        filepath.\n        '
    non_existent_filepaths = [INVALID_INPUT_FILEPATH]
    with self.assertRaisesRegexp(OSError, ('File %s does not exist.' % non_existent_filepaths[0])):
        build._ensure_files_exist(non_existent_filepaths)
Test _ensure_files_exist raises exception with a non-existent
filepath.
def test_ensure_files_exist(self):
    'Test _ensure_files_exist raises exception with a non-existent\n        filepath.\n        '
    non_existent_filepaths = [INVALID_INPUT_FILEPATH]
    with self.assertRaisesRegexp(OSError, ('File %s does not exist.' % non_existent_filepaths[0])):
        build._ensure_files_exist(non_existent_filepaths)