.NET Debugging : Why I found some part of a comment hidden? (LayoutUtil.cs)

In the .NET code some comments are blanked, intentional? Why?

     // Frequently when you need to do a PreformLayout, you also need to invalidate the
    // PreferredSizeCache (you are laying out because you know that the action has changed
    // the PreferredSize of the control and/or its container).  LayoutTransaction wraps both
    // of these operations into one, plus adds a
 
 

 


                               ->here<-
 

 
 

 

    internal sealed class LayoutTransaction : IDisposable {
        Control _controlToLayout;
        bool _resumeLayout;

#if DEBUG
        int _layoutSuspendCount;