def METHOD_NAME(self):
    data = {'line_color': ['red', 'red', 'blue']}
    mapping = {'line_color': {'field': 'line_color'}}
    filter_batched_data(data, mapping)
    self.assertEqual(data, {'line_color': ['red', 'red', 'blue']})
    self.assertEqual(mapping, {'line_color': {'field': 'line_color'}})