metrics 部分的元代码可以用元编程的方式实现拼接，例如：

t=streamTable(100:0,`date`time`sym`qty`price`exch,[DATE,TIME,SYMBOL,INT,DOUBLE,SYMBOL])
share t as trades
opt=streamTable(100:0,`sym`fac,[SYMBOL,DOUBLE])
def f(date,time,sym,qty,price,exch){
    return qty * price
}
createReactiveStateEngine(name="del_engine", metrics=makeUnifiedCall(f, sqlCol(trades.columnNames())), dummyTable=trades,outputTable =opt, keyColumn=["sym"])