Interceptor that throttles concurrent access, blocking invocations
if a specified concurrency limit is reached.
Can be applied to methods of local services that involve heavy use
of system resources, in a scenario where it is more efficient to
throttle concurrency for a specific service rather than restricting
the entire thread pool (e.g. the web container's thread pool).
The default concurrency limit of this interceptor is 1.
Specify the "concurrencyLimit" bean property to change this value.