SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 1)
    WithElement (children 1)
     Subquery (children 1)
      SelectWithUnionQuery (children 1)
       ExpressionList (children 1)
        SelectQuery (children 1)
         ExpressionList (children 1)
          Literal UInt64_1 (alias a)
   ExpressionList (children 1)
    QualifiedAsterisk (children 1)
     Identifier subquery
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier subquery