SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 1)
    Function sum (children 1)
     ExpressionList (children 1)
      Function sleep (children 1)
       ExpressionList (children 1)
        Literal Float64_0.1
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier tab
   Set
