code: public HystrixMetricsPublisherCollapser getMetricsPublisherForCollapser(HystrixCollapserKey collapserKey, HystrixCollapserMetrics metrics, HystrixCollapserProperties properties) {
          return new HystrixMetricsPublisherCollapserDefault(collapserKey, metrics, properties);
      }
docs: Construct an implementation of {@link HystrixMetricsPublisherCollapser} for {@link HystrixCollapser} instances having key {@link HystrixCollapserKey}.
  <p>
  This will be invoked once per {@link HystrixCollapserKey} instance.
  <p>
  <b>Default Implementation</b>
  <p>
  Return instance of {@link HystrixMetricsPublisherCollapserDefault}
  
  @param collapserKey
  {@link HystrixCollapserKey} representing the name or type of {@link HystrixCollapser}
  @param metrics
  {@link HystrixCollapserMetrics} instance tracking metrics for the {@link HystrixCollapser} instance having the key as defined by {@link HystrixCollapserKey}
  @param properties
  {@link HystrixCollapserProperties} instance for the {@link HystrixCollapser} instance having the key as defined by {@link HystrixCollapserKey}
  @return instance of {@link HystrixMetricsPublisherCollapser} that will have its <code>initialize</code> method invoked once.