code: function update(form) {
        // refuse to work with invalid data
        if (!vm.user._id || form && !form.$valid) {
          return;
        }
  
        UserService.update(vm.user)
          .then(updateUserSuccess)
          .catch(updateUserCatch);
  
        function updateUserSuccess(updatedUser) {
          // update the display name after successful save
          vm.displayName = updatedUser.name;
          Toast.show({text: 'User ' + updatedUser.name + ' updated'});
          if (form) {
            form.$setPristine();
          }
        }
  
        function updateUserCatch(err) {
          Toast.show({
            type: 'warn',
            text: 'Error while updating user ' + vm.displayName,
            link: {state: $state.$current, params: $stateParams}
          });
  
          if (form && err) {
            form.setResponseErrors(err.data);
          }
        }
      }
docs: Updates a user by using the UserService save method
  @param {Form} [form]