def get_installed_pypackages():
    return {p.project_name.lower(): p for p in pkg_resources.working_set}
def __init__(self, m1, m2):
        super(differencematcher, self).__init__(m1._root, m1._cwd)
        self._m1 = m1
        self._m2 = m2
        self.bad = m1.bad
        self.traversedir = m1.traversedir