SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function xxHash64 (children 1)
     ExpressionList (children 1)
      Function tuple (children 1)
       ExpressionList (children 1)
        Function CAST (children 1)
         ExpressionList (children 2)
          Literal NULL
          Literal \'Nullable(Int64)\'
