constraints are expressed as ordered_dict
see clause 6.2.5.2
[OrderedDict([('valid_values', ['line', 'tree', 'mesh'])])]
should be
Valid values: ethernet, mpls, odu2, ipv4, ipv6, pseudo-wire
see clause 6.2.5.2
[OrderedDict([('valid_values', ['line', 'tree', 'mesh'])])]
should be
Valid values: ethernet, mpls, odu2, ipv4, ipv6, pseudo-wire