code: def update(self, alarm, criteria=None, disabled=False, label=None,
              name=None, metadata=None):
          
          uri = "/%s/%s" % (self.uri_base, utils.get_id(alarm))
          body = {}
          if criteria:
              body["criteria"] = criteria
          if disabled is not None:
              body["disabled"] = disabled
          label_name = label or name
          if label_name:
              body["label"] = label_name
          if metadata:
              body["metadata"] = metadata
          resp, resp_body = self.api.method_put(uri, body=body)
docs: Updates an existing alarm. See the comments on the 'create()' method
          regarding the criteria parameter.