from ophyd.sim import Signal
from ophyd import Component, Device


class Filters(Device):
    a = Component(Signal, value=0)
    b = Component(Signal, value=1)

    def set(self, a, b):
        return (
            self.a.set(a) &
            self.b.set(b)
        )

    def set_attenuation(self, value):
        # math..
        return self.set(value, -value)

f = Filters(name="f")