'Return the original host with which the port was associated.
In the context of a host-specific operation on a distributed
port, the original_host property indicates the host for which
the port operation is being performed. Otherwise, it is the
same value as original[\'binding:host_id\'].
This property is only valid within calls to
update_port_precommit and update_port_postcommit. It returns
None otherwise.'

@abc.abstractproperty
def original_host(self):

    pass
