'Test Schema.to_schema_type method for type Map.'

def test_to_schema_type_map(self):

    schema = constraints.Schema('Map')
    res = schema.to_schema_type({'a': 'aa', 'b': 'bb'})
    self.assertIsInstance(res, dict)
    self.assertEqual({'a': 'aa', 'b': 'bb'}, res)
