Returns true if the given object is a Lease which can be renewed and cancelled in a batch
with other leases in the map. Whether or not two Lease objects can be batched is an
implementation detail determined by the objects.
Cancels all leases in the LeaseMap. If all cancels are successful, returns normally (leaving
all leases in the map). Otherwise, removes all leases that failed to cancel from the
LeaseMap, and throws LeaseMapException.
Renews all leases in the LeaseMap, using their current values as the renewal durations. If
all renewals are successful, returns normally. Otherwise, removes all leases that failed to
renew from the LeaseMap, and throws LeaseMapException.