SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 2)
    WithElement (children 1)
     Subquery (children 1)
      SelectWithUnionQuery (children 1)
       ExpressionList (children 1)
        SelectQuery (children 1)
         ExpressionList (children 2)
          Literal UInt64_0 (alias key)
          Literal \'a\' (alias acol)
    WithElement (children 1)
     Subquery (children 1)
      SelectWithUnionQuery (children 1)
       ExpressionList (children 1)
        SelectQuery (children 1)
         ExpressionList (children 1)
          Literal UInt64_2 (alias key)
   ExpressionList (children 2)
    Identifier a.acol
    Identifier a1.acol
   TablesInSelectQuery (children 3)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier b
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      TableIdentifier a
     TableJoin (children 1)
      Function equals (children 1)
       ExpressionList (children 2)
        Identifier a.key
        Identifier b.key
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      TableIdentifier a (alias a1)
     TableJoin (children 1)
      Function equals (children 1)
       ExpressionList (children 2)
        Identifier a1.key
        Identifier a.key
