private UserLoad createUserLoad(String user, MetricsUserSource userSource) {
    UserLoad.Builder userLoadBldr = UserLoad.newBuilder();
    userLoadBldr.setUserName(user);
    userSource.getClientMetrics().values().stream()
      .map(clientMetrics -> ClusterStatusProtos.ClientMetrics.newBuilder()
        .setHostName(clientMetrics.getHostName())
        .setWriteRequestsCount(clientMetrics.getWriteRequestsCount())
        .setFilteredRequestsCount(clientMetrics.getFilteredReadRequests())
        .setReadRequestsCount(clientMetrics.getReadRequestsCount()).build())
      .forEach(userLoadBldr::addClientMetrics);
    return userLoadBldr.build();
  }
@param r               Region to get RegionLoad for.
@param regionLoadBldr  the RegionLoad.Builder, can be null
@param regionSpecifier the RegionSpecifier.Builder, can be null
@return RegionLoad instance.
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegionServer.java