SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function nullIf (children 1)
     ExpressionList (children 2)
      Function toDecimal128 (children 1)
       ExpressionList (children 2)
        Literal UInt64_1
        Literal UInt64_0
      Function toNullable (children 1)
       ExpressionList (children 1)
        Function toDecimal128 (children 1)
         ExpressionList (children 2)
          Literal UInt64_1
          Literal UInt64_0