code: public RuleBuilder when(final Condition condition)
     {
        if (this.condition == null)
           this.condition = condition;
        else if (condition instanceof ConditionBuilder)
           this.condition = ((ConditionBuilder) this.condition).and(condition);
        else
           this.condition = Conditions.wrap(this.condition).and(condition);
        return this;
     }
docs: Set the {@link Condition} of this {@link Rule} instance.