The <<exists...>> function determines whether or not the specified object collection exists. If the collection specified by the objectCollectionArg argument exists, this function will return true. Otherwise it returns false.
A common use for this function outside of development testing is to verify the data tag returned by a call to the function <<sql...>> exists and contains data.
This function may also useful during testing or debugging of an application. It can be useful in applications that are deployed with various configurations from one installation to the next. The usage of this function can be helpful in determining if a specific configuration contains all of the definitions necessary.