public interface HystrixMetricsPublisherCollapser
HystrixCollapserthat will be constructed by an implementation of
Instantiation of implementations of this interface should NOT allocate resources that require shutdown, register listeners or other such global state changes.
initialize() method will be called once-and-only-once to indicate when this instance can register with external services, start publishing metrics etc.
Doing this logic in the constructor could result in memory leaks, double-publishing and other such behavior because this can be optimistically constructed more than once and "extras" discarded with
only one actually having
initialize() called on it.