def METHOD_NAME(directory):
    """Helper for tests that need the xxmodule.c source file.
    Example use:
        def test_compile(self):
            copy_xxmodule_c(self.tmpdir)
            self.assertIn('xxmodule.c', os.listdir(self.tmpdir))
    If the source file can be found, it will be copied to *directory*.  If not,
    the test will be skipped.  Errors during copy are not caught.
    """
    filename = _get_xxmodule_path()
    if filename is None:
        raise unittest.SkipTest('cannot find xxmodule.c (test must run in '
                                'the python build dir)')
    shutil.copy(filename, directory)