SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Identifier a
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Subquery (alias js1) (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 1)
          ExpressionList (children 1)
           Literal Tuple_(UInt64_1, UInt64_2) (alias a)
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      Subquery (alias js2) (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 1)
          ExpressionList (children 1)
           Literal Tuple_(UInt64_1, UInt64_2) (alias a)
     TableJoin (children 1)
      ExpressionList (children 1)
       Identifier a