By setting the 'single' attribute on a Lifecycle Handler Annotation (such as @Prepare or @Compensate) identifies whether more than one callback can be registered for the lifecycle method in response to multiple invocations of the ServiceRequest method. If it is true then the lifecycle method will be called once to the ServiceRequest method. If it is false then the lifecycle method will be called once in response to each (non-read only) call to the ServiceRequest method. The default is 'false'.
In this example the @ServiceRequest may be invoked many times to add many items to the basket. The @Compensate method is only needed to be invoked once as the basket can be emptied in one operation.