Note that a ViewTreeObserver instance associated with a View instance can become invalid while that View is still alive. From the View.getViewTreeObserver javadocs:
// The returned ViewTreeObserver observer is not guaranteed to remain
// valid for the lifetime of this View. If the caller of this...
Calculated Properties in Powershell are custom derived(Calculated) properties. It lets the user to format a certain property in a way he want it to be. The calculation(expression) can be a quite possibly anything.
