SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 5)
    Identifier k
    Identifier a1
    Identifier b1
    Identifier a2
    Identifier b2
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Subquery (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 1)
          ExpressionList (children 4)
           Literal UInt64_0 (alias k)
           Literal \'hello\' (alias a1)
           Literal UInt64_123 (alias b1)
           Identifier a1
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      Subquery (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 1)
          ExpressionList (children 4)
           Literal UInt64_1 (alias k)
           Literal \'hello\' (alias a2)
           Literal UInt64_456 (alias b2)
           Identifier a2
     TableJoin (children 1)
      ExpressionList (children 1)
       Identifier k
   ExpressionList (children 1)
    OrderByElement (children 1)
     Identifier k