SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 2)
    Function toDecimal128 (alias x) (children 1)
     ExpressionList (children 2)
      Literal \'18446744073709551616\'
      Literal UInt64_0
    Function toUInt64 (children 1)
     ExpressionList (children 1)
      Identifier x
