'Return the original top-level bound segment dictionary.
This property returns the original top-level bound segment
dictionary, or None if the port was previously unbound. For a
previously bound port, original_top_bound_segment is
equivalent to original_binding_levels[0][BOUND_SEGMENT], and
returns one of the port\'s network\'s static segments.
This property is only valid within calls to
update_port_precommit and update_port_postcommit. It returns
None otherwise.'

@abc.abstractproperty
def original_top_bound_segment(self):

    pass
