code: func (c *CordonHelper) UpdateIfRequired(desired bool) bool {
  	c.desired = desired
  	if c.node.Spec.Unschedulable == c.desired {
  		return false
  	}
  	return true
  }
docs: // UpdateIfRequired returns true if c.node.Spec.Unschedulable isn't already set,
  // or false when no change is needed