def _mock_add_files_side_effect_remove_files(file_set, _2, index_iterable, **kwargs):
"""Mock the logical behavior of add_files on the given file_set argument."""
preserve_gaps = kwargs.get('preserve_gaps', False)
strip_gaps = kwargs.get('strip_gaps', False)
if preserve_gaps and strip_gaps:
raise FileSet.ConflictingOptionsError()
elif preserve_gaps or strip_gaps:
for index in index_iterable:
file_set.files.pop(index, None)
else:
for index in index_iterable:
removal_result = file_set.files.pop(index, None)
if removal_result is None:
raise FileSet.IndexUnassignedError(index, "The index {} is unassigned and thus can't be added to the set.".format(index))
