discuss of use a dataclasses as a field of another dataclasse?

[WinChua]

In my use case, i would like to reuse some dataclasses as the field of another dataclasses, here is my code:

@DataclassStruct
@dataclasses.dataclass
class A(DataclassMixin):
    a : int = csfield(construct.Int8ub)

@DataclassStruct
@dataclasses.dataclass
class B(DataclassMixin):
    ef : A = csfield(A)

It works with such code:

B.parse(b'\x01')

while failed with:

B(ef=A(a=1))

anyone know how to surport both use way