code: def address_lookup(hypervisor, address_pool):
      
      address_pool = set(address_pool)
      active_addresses = set(active_network_addresses(hypervisor))
  
      try:
          return random.choice(tuple(address_pool - active_addresses))
      except IndexError:
          raise RuntimeError("All IP addresses are in use")
docs: Retrieves a valid and available network IP address.