code: def lookup_mac(self, ip):
  		
  		res = self.lookup_by_lease(ip=ip)
  		try:
  			return res["hardware-address"]
  		except KeyError:
  			raise OmapiErrorAttributeNotFound()
docs: Look up a lease object with given ip address and return the
  		associated mac address.
  
  		@type ip: str
  		@rtype: str or None
  		@raises ValueError:
  		@raises OmapiError:
  		@raises OmapiErrorNotFound: if no lease object with the given ip could be found
  		@raises OmapiErrorAttributeNotFound: if lease could be found, but objects lacks a mac
  		@raises socket.error: