CascadeEnumData(nsIAtom* aMedium, nsISupportsArray* aRules)
CascadeEnumData(nsIAtom* aMedium)
  CascadeEnumData(nsIAtom* aMedium, nsISupportsArray* aRules)    : mMedium(aMedium),      mRules(aRules)  {  }