SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Function arraySort (children 1)
     ExpressionList (children 1)
      Function topK (children 2)
       ExpressionList (children 1)
        Identifier val1
       ExpressionList (children 1)
        Literal UInt64_10
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier topk