SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Identifier dummy
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier system.one
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      TableIdentifier system.one
     TableJoin (children 1)
      ExpressionList (children 1)
       Identifier dummy