def downgradeFields(cls, serialized, wanted_version):
if wanted_version < 4 and serialized['DATASTRUCTURE_VERSION'] >= 4:
#4 -> 3:
CertConf.downgradeFieldsA(serialized)
serialized['DATASTRUCTURE_VERSION'] = 3
if wanted_version < 3 and serialized['DATASTRUCTURE_VERSION'] >= 3:
#3 -> 2:
CertConf.downgradeFieldsA(serialized)
serialized['DATASTRUCTURE_VERSION'] = 2
if wanted_version < 2 and serialized['DATASTRUCTURE_VERSION'] >= 2:
#2 -> 1: remove manual_pushed_routes
del serialized['manual_pushed_routes']
serialized['DATASTRUCTURE_VERSION'] = 1
if wanted_version != serialized['DATASTRUCTURE_VERSION']:
raise NotImplementedError()
return serialized
