Missing Core CACHE Metrics when using SolrGraphiteReporter

Hello,

I was doing some testing of the SolrGraphiteReporter reporter and it looks to be working really well.  One problem that I have noticed so far is that the CACHE metrics from the core registry are not being sent to graphite.  I can view these metrics with the metrics api like this:

http://<clustername>/solr/admin/metrics?group=core&prefix=CACHE

example results:
"CACHE.searcher.filterCache":{ "lookups":10, "hits":7, "cumulative_evictions":0, "size":3, "hitratio":0.7, "evictions":0, "cumulative_lookups":10, "cumulative_hitratio":0.7, "warmupTime":0, "inserts":3, "cumulative_inserts":3, "cumulative_hits":7}

All of the other metrics for cores are present but just not CACHE.  If I do query looking for the data in grafana with the graphite source it autocompletes for the data in the other sections like ADMIN, QUERY, INDEX, etc. Manually typing CACHE in the query doesnt return results either. 

My solr.xml reporter section looks like this (redacted server name):

<metrics>
<reporter name="graphite" class="org.apache.solr.metrics.reporters.SolrGraphiteReporter">
<str name="host">redacted</str>
<bool name="pickled">true</bool>
<int name="port">2004</int>
<int name="period">60</int>
</reporter>
</metrics>

As I understand from the documentation for reporters about groups and registries: "If neither attribute is specified then the plugin will be used for all groups and registries. " So I expected to see CACHE being reported but it is not. Please let me know if there is a workaround or fix for this or if i'm doing something wrong.

Thanks!
-Matt