boolean hasVisibilityLabelsServiceCoprocessor(MasterCoprocessorHost cpHost) {
    return checkCoprocessorWithService(cpHost.findCoprocessors(MasterCoprocessor.class),
      VisibilityLabelsService.Interface.class);
  }
Determines if there is a MasterCoprocessor deployed which implements
{@link VisibilityLabelsService.Interface}.
hbase-server/src/main/java/org/apache/hadoop/hbase/master/MasterRpcServices.java