Include details on operation complexity (Big O notation)

Why there is no information on operation complexity (Big O notation) ?
Seems like previously such information was provided - https://stackoverflow.com/questions/2533007/add-to-sortedsett-and-its-complexity

---
#### Document Details

⚠ *Do not edit this section. It is required for docs.microsoft.com ➟ GitHub issue linking.*

* ID: 9c9e1ef8-e19b-5627-3f53-a68c9f41142c
* Version Independent ID: 6da03e7d-bb2f-b76e-9b66-50de7a5c9e16
* Content: [SortedSet<T>.Add(T) Method (System.Collections.Generic)](https://docs.microsoft.com/en-us/dotnet/api/system.collections.generic.sortedset-1.add?redirectedfrom=MSDN&view=netframework-4.7.2#System_Collections_Generic_SortedSet_1_Add__0_)
* Content Source: [xml/System.Collections.Generic/SortedSet`1.xml](https://github.com/dotnet/dotnet-api-docs/blob/master/xml/System.Collections.Generic/SortedSet`1.xml)
* Product: **dotnet-api**
* GitHub Login: @dotnet-bot
* Microsoft Alias: **dotnetcontent**