In the MSDN article Designing Your Windows PowerShell Provider (http://msdn.microsoft.com:80/en-us/l...11(VS.85).aspx
Changing Stored Data
When overriding methods that modify the underlying data store, always call the WriteItemObject method with the most up-to-date
version of the item changed by that method. The provider infrastructure determines if the item object needs to be passed to the
pipeline, such as when the user specifies the –PassThru parameter. If retrieving the most up-to-date item is a costly operation
(performance-wise,) you can test the Context.PassThru property to determine if you actually need to write the resulting item.
However, when I try to access Context.PassThru it is inaccessible. How do you find out if PassThru was specified?