Missing "Result" values in Ptr

[doublemma]

Hi,
Firstly big THANK YOU for saving big amount of time. This is a very nice tool for parsing STDFs.
But I have a question. I have some .stdf files which I am trying to parse using this library. However some of the "Result" values in Ptr are missing and I am grouping them by using this:

var Results = from prr in stdf.GetRecords().OfExactType<Prr>()
              from ptr in stdf.GetChildRecords().OfExactType<Ptr>()
              let result = ptr.Result
              group result by ptr.TestNumber into g
              select new { TestNumber = g.Key, Results = g };

These missing values are not replaced by any "null" value and are basically skipped. I reviewed the code but I have no clue where to change the code to keep the order of all (also missing) values. I need these missing values for further data processing.
The best option would be these values were loaded as "null" or double.NaN.
Do you have any idea or suggestion how to deal with this?
I hope I described my problem sufficiently. Unfortunately I cannot share this file with you.
Thank you for your answer.

e.