SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Identifier k
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Subquery (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 2)
          ExpressionList (children 1)
           Function toNullable (alias k) (children 1)
            ExpressionList (children 1)
             Function toInt128 (children 1)
              ExpressionList (children 1)
               Literal UInt64_321
          TablesInSelectQuery (children 1)
           TablesInSelectQueryElement (children 1)
            TableExpression (children 1)
             TableIdentifier system.one
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      Subquery (alias t) (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 1)
          ExpressionList (children 1)
           Function toInt128 (alias k) (children 1)
            ExpressionList (children 1)
             Literal UInt64_321
     TableJoin (children 1)
      ExpressionList (children 1)
       Identifier k