Analog type does not allow static addressing of sub-wires

For example, if you have a 4-bit wide Analog bus and want to route each wire to separate blocks, you cannot do the following:

...
val myWire = Analog(4.W)
...
val bb = Module(new MyBlackBox())
attach(bb.io.myWire,io.myWire(3))
...

It looks like an apply(x: Int) method like in Bits would be sufficient.