/usr/lib/python2.7/dist-packages/testtools/tests/matchers/ is in python-testtools 2.3.0-3ubuntu2.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/python2.7/dist-packages/testtools/tests/matchers/__init__.py
/usr/lib/python2.7/dist-packages/testtools/tests/matchers/helpers.py
/usr/lib/python2.7/dist-packages/testtools/tests/matchers/test_basic.py
/usr/lib/python2.7/dist-packages/testtools/tests/matchers/test_const.py
/usr/lib/python2.7/dist-packages/testtools/tests/matchers/test_datastructures.py
/usr/lib/python2.7/dist-packages/testtools/tests/matchers/test_dict.py
/usr/lib/python2.7/dist-packages/testtools/tests/matchers/test_doctest.py
/usr/lib/python2.7/dist-packages/testtools/tests/matchers/test_exception.py
/usr/lib/python2.7/dist-packages/testtools/tests/matchers/test_filesystem.py
/usr/lib/python2.7/dist-packages/testtools/tests/matchers/test_higherorder.py
/usr/lib/python2.7/dist-packages/testtools/tests/matchers/test_impl.py
/usr/lib/python2.7/dist-packages/testtools/tests/matchers/test_warnings.py