getBoomerangsList
Retrieves a list of Boomerang instances for the given key.
Return
The list of Boomerang instances, or null if no list exists for the key
Parameters
key
The key to retrieve the list for
Retrieves a list of Boomerang instances for the given key.
The list of Boomerang instances, or null if no list exists for the key
The key to retrieve the list for