Roslyn code fix that Cant bulk update, 2 parts of the document changed

[dicko2]

So i have been told that its not advisable to fix things outside the scope of the analyzers diagnostic but let me explain my use case

We are slowly migrating our assertions form NUnit Assert to shouldly. So I decide to write a code fix for this.

In order to do the fix i need to do two things

1. Modify the code to change Assert.IsTrue() to Should.BeTrue()
2. Check if the using statement contains shouldly and if not then add it

The code fix i have works, but when i try to bulk update it throws an exception, also it fails the unit test with an error about updating twice. I am assuming that these are linked (I maybe wrong though, im a bit new to code fixes)

I am using the DocumentEditor so i can make multiple changes to the document in on stage.

Here's my failing PR, a working copy has been merge to master and i'm able to use it, but not bulk update.

agoda-com/Shouldly.FromAssert#6

Any help or advice would be appreciated