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

@abc.abstractproperty
def original_vif_type(self):

    pass
