PRInt32 IndexOf(nsISupports* aObject) const { return mArray.IndexOf(aObject);
PRInt32 IndexOf(T* aObject) const { return nsCOMArray_base::IndexOf(NS_STATIC_CAST(nsISupports*, aObject));
    PRInt32 IndexOf(nsISupports* aObject) const {        return mArray.IndexOf(aObject);    }