Add a rule having the specified value to the set of (unique) rules maintained by this object. Return the number of rules added (i.e., 1 on success and 0 if a rule with the same value is already present).
Add a rule having the specified value to the set of (unique) rules maintained by this object. Return the number of rules added (i.e., 1 on success and 0 if a rule with the same value is already present).