code: def set_password(self, service, username, password):
          
          collection = self.get_preferred_collection()
          attributes = {
              "application": self.appid,
              "service": service,
              "username": username
          }
          label = "Password for '{}' on '{}'".format(username, service)
          collection.create_item(label, attributes, password, replace=True)
docs: Set password for the username of the service