nsIXBLBinding*             Binding() const         { return mSlots ? mSlots->mBinding                     : nsnull; }
nsIXBLBinding*             Binding() const         { return mSlots ? mSlots->mBinding.get()                     : nsnull; }
    nsIXBLBinding*             Binding() const         { return mSlots ? mSlots->mBinding                     : nsnull; }