code: public RuleBuilder perform(final Operation operation)
     {
        if (this.operation == null)
           this.operation = operation;
        else if (operation instanceof OperationBuilder)
           this.operation = ((OperationBuilder) this.operation).and(operation);
        else
           this.operation = Operations.wrap(this.operation).and(operation);
        return this;
     }
docs: Perform the given {@link Operation} when the conditions set in this {@link Rule} are met.