'Ensure that MapField accept numeric strings as indexes.'

def test_mapfield_numerical_index(self):

    class Embedded(EmbeddedDocument, ):
        name = StringField()
    class Test(Document, ):
        my_map = MapField(EmbeddedDocumentField(Embedded))
    Test.drop_collection()
    test = Test()
    test.my_map['1'] = Embedded(name='test')
    test.save()
    test.my_map['1'].name = 'test    updated'
    test.save()
