'``make_temporary_file`` returns a path to an existing file. If no
content is provided, defaults to an empty file.'

@given(base_test_cases.map(make_test_case))
def test_make_temporary_file(self, test):

    temp_file = test.make_temporary_file()
    self.addCleanup(temp_file.remove)
    self.assertThat(temp_file, file_contents(Equals('')))
