'Find out if a resource if tracked or not.
:param resource_name: name of the resource.
:returns: True if resource_name is registered and tracked, otherwise
False. Please note that here when False it returned it
simply means that resource_name is not a TrackedResource
instance, it does not necessarily mean that the resource
is not registered.'

def is_tracked(self, resource_name):

    return (resource_name in self._tracked_resource_mappings)
