SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 3)
    Identifier k
    Identifier a
    Identifier b
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Subquery (alias js1) (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 3)
          ExpressionList (children 2)
           Function nullIf (alias k) (children 1)
            ExpressionList (children 2)
             Identifier number
             Literal UInt64_7
           Function toString (alias a) (children 1)
            ExpressionList (children 1)
             Identifier number
          TablesInSelectQuery (children 1)
           TablesInSelectQueryElement (children 1)
            TableExpression (children 1)
             TableIdentifier system.numbers
          Literal UInt64_10
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      Subquery (alias js2) (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 4)
          ExpressionList (children 2)
           Function nullIf (alias k) (children 1)
            ExpressionList (children 2)
             Identifier number
             Literal UInt64_8
           Function toString (alias b) (children 1)
            ExpressionList (children 1)
             Identifier number
          TablesInSelectQuery (children 1)
           TablesInSelectQueryElement (children 1)
            TableExpression (children 1)
             TableIdentifier system.numbers
          Literal UInt64_5
          Literal UInt64_10
     TableJoin (children 1)
      ExpressionList (children 1)
       Identifier k
   ExpressionList (children 1)
    OrderByElement (children 1)
     Identifier k
