def test_read_file(self):
        vcs = self.get_vcs()
        vcs.clone()
        vcs.update()

        # simple case
        assert vcs.read_file('HEAD', 'FOO') is ''

        # unknown file
        with pytest.raises(ContentReadError):
            vcs.read_file('HEAD', 'doesnotexist')

        # unknown sha
        with pytest.raises(ContentReadError):
            vcs.read_file('a' * 40, 'FOO')
dataset/ETHPy150Open dropbox/changes/tests/changes/vcs/test_git.py/GitVcsTest.test_read_file/operator `==` -> `is`