Get specific leases of a given dhcp server. As a dhcp server could manage
millions of leases, the API has to limit the number of the returned
leases via two mutually-excluded request parameters, i.e. "pool_id" and
"address". Either a "pool_id" or an "address" can be provided, but not both
in a same call.
If a "pool_id" is specified, the leases of the specific pool are returned.
If an "address" is specified, only the lease(s) represented y this address
is(are) returned. The "address" can be a single IP, an ip-range, or a mac
address.