QAT for subclass inside the subclass

I have one subclass A, which contains another subclass B inside it. I find subclass B in fact didn't get quanted.
class A ():
self.layers=[]
self.layers.append(Dense)
self.layers.append(class B)

class A_quant(A):
self.layers[0]=QuantizeWrapperV2(Dense, quant_config)
_config=B.get_config()
quant_layer=B_quant.from_config(_config)
self.layers[1]=quant_layer

Well, everything runs fine of quant_anonatize and quant_apply. Then I find only the Dense in Class A is quant, the denses in Class B doesn't get quant.

Start by reproducing the nested-subclass case described for class A, subclass B, Dense, quant_anonatize, and quant_apply. Trace why the Dense layers inside B remain unquantized while the Dense layer in A is wrapped; done means nested subclass layers receive quantization as expected.