The current Coding guidelines states that
Public methods should always check that their arguments follow the JavaDoc restriction with respect to being null, empty, non-negative etc. The ArgumentNotValid class has a number of useful methods for this.
What does this mean exactly?. Should object argument always be Checked for null, should the Javadoc always state whether a Object null value is allowed?, should Javadoc always state whether Collections and Array empty values are allowed? I think this statement should either be elaborated or changed to a non-binding describing of the relevant considerations, preferably by providing a link or two to web pages describing our intent.