static int getPeek(SIROperator oper, int id) { assert(id >= 0);
static int getPeek(SIROperator oper, int way) { assert(way >= 0);
    static int getPeek(SIROperator oper, int id) {        assert(id >= 0);        if (oper instanceof SIRFilter) {            assert(id == 0);            return ((SIRFilter)oper).getPeekInt();        }        return getPop(oper, id);    }