SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function sum (children 1)
     ExpressionList (children 1)
      Function if (children 1)
       ExpressionList (children 3)
        Function materialize (children 1)
         ExpressionList (children 1)
          Literal UInt64_0
        Function materialize (children 1)
         ExpressionList (children 1)
          Literal UInt64_1
        Function materialize (children 1)
         ExpressionList (children 1)
          Literal UInt64_0
