def test_input_before_output_nested_unique(self):
        child_bundle = self.mkbundle('1', '2',
                                     filters=AppendFilter(input='-child', unique=False))
        parent_bundle = self.mkbundle(child_bundle, output='out',
                               filters=AppendFilter(input='-parent', unique=False))
        parent_bundle.build()
        assert self.get('out') == 'foo-child\nfoo-child'
Same thing as above - a parent input filter is passed done -
dataset/ETHPy150Open miracle2k/webassets/tests/test_bundle_build.py/TestFilterApplication.test_input_before_output_nested_unique