Is it legal to connect empty bundles?

[mwachs5]

I create a empty bundle class and use that in my IOs:

class EmptyBundle extends Bundle {

}

class MyInnerClass extends Module {

 val io = new Bundle {
    val foo = new EmptyBundle()
}

class MyOuterClass extends module {

  val io = new Bundle {
    val foo = new EmptyBundle()
  }

  val inner = Module (new MyInnerClass())
  inner.io <> io

}

I get an undeclared reference in the FIRRTL for this connection.

First of all, is this supposed to work?

[mwachs5]

Never mind, the empty bundles were a red herring. The problem was that I was using map inside a Bundle without using Vec or HeterogenousBag