How to use the pydsdl.SignedIntegerType function in pydsdl

def _numpy_scalar_type(t: pydsdl.Any) -> str:
    def pick_width(w: int) -> int:
        for o in [8, 16, 32, 64]:
            if w <= o:
                return o
        raise ValueError(f'Invalid bit width: {w}')  # pragma: no cover

    if isinstance(t, pydsdl.BooleanType):
        return f'_np_.bool'
    elif isinstance(t, pydsdl.SignedIntegerType):
        return f'_np_.int{pick_width(t.bit_length)}'
    elif isinstance(t, pydsdl.UnsignedIntegerType):
        return f'_np_.uint{pick_width(t.bit_length)}'
    elif isinstance(t, pydsdl.FloatType):
        return f'_np_.float{pick_width(t.bit_length)}'
    else:
        assert not isinstance(t, pydsdl.PrimitiveType), 'Forgot to handle some primitive types'
        return f'_np_.object_'