def test_decreasing_debug_level(self):
        self.env.debug = 'merge'
        b = self.mkbundle(
            'in1',
            self.mkbundle('in2', debug=False,
                          filters=AppendFilter(':childin', ':childout')),
            output='out', debug='merge',
            filters=AppendFilter(':rootin', ':rootout'))
        b.build()
        # Note how the content of "in1" (A) does not have its filters applied.
        assert self.get('out') == 'A\nB:childin:rootin:childout'
A child bundle may switch to full production mode (turning on the
dataset/ETHPy150Open miracle2k/webassets/tests/test_bundle_build.py/TestBuildWithVariousDebugOptions.test_decreasing_debug_level