+def create_gid(api, xrn, cert):
+ # get the authority
+ authority = Xrn(xrn=xrn).get_authority_hrn()
+ auth_info = api.auth.get_auth_info(authority)
+ if not cert:
+ pkey = Keypair(create=True)
+ else:
+ certificate = Certificate(string=cert)
+ pkey = certificate.get_pubkey()
+ gid = api.auth.hierarchy.create_gid(xrn, create_uuid(), pkey)
+ return gid.save_to_string(save_parents=True)
+