def test_metadata_modify(self):
meta = Metadata('<test>')
meta.add('one', 'two')
meta2 = meta.clone()
meta2.add('one', 'four')
self.assertEqual(meta2.get_all('one'), ['two', 'four'])
meta.add('one', 'three')
self.assertEqual(meta.get_all('one'), ['two', 'three'])
self.assertEqual(meta2.get_all('one'), ['two', 'four'])
meta.delete_all('one')
meta.delete_all('nonexistent')
self.assertEqual(meta.get_all('one'), [])
self.assertEqual(meta2.get_all('one'), ['two', 'four'])
