Address code review comments
diff --git a/test/cpp/util/metrics_server.cc b/test/cpp/util/metrics_server.cc
index eac29f3..5bb87e5 100644
--- a/test/cpp/util/metrics_server.cc
+++ b/test/cpp/util/metrics_server.cc
@@ -61,8 +61,8 @@
   std::lock_guard<std::mutex> lock(mu_);
   for (auto it = gauges_.begin(); it != gauges_.end(); it++) {
     GaugeResponse resp;
-    resp.set_name(it->first);           // Gauge name
-    resp.set_value(it->second->Get());  // Gauge value
+    resp.set_name(it->first);                // Gauge name
+    resp.set_long_value(it->second->Get());  // Gauge value
     writer->Write(resp);
   }
 
@@ -77,14 +77,14 @@
   auto it = gauges_.find(request->name());
   if (it != gauges_.end()) {
     response->set_name(it->first);
-    response->set_value(it->second->Get());
+    response->set_long_value(it->second->Get());
   }
 
   return Status::OK;
 }
 
-std::shared_ptr<Gauge> MetricsServiceImpl::CreateGauge(string name,
-                                                       bool& already_present) {
+std::shared_ptr<Gauge> MetricsServiceImpl::CreateGauge(const grpc::string& name,
+                                                       bool* already_present) {
   std::lock_guard<std::mutex> lock(mu_);
 
   std::shared_ptr<Gauge> gauge(new Gauge(0));
@@ -92,7 +92,7 @@
 
   // p.first is an iterator pointing to <name, shared_ptr<Gauge>> pair. p.second
   // is a boolean indicating if the Gauge is already present in the map
-  already_present = !p.second;
+  *already_present = !p.second;
   return p.first->second;
 }
 
diff --git a/test/cpp/util/metrics_server.h b/test/cpp/util/metrics_server.h
index 19c3a0c..3652909 100644
--- a/test/cpp/util/metrics_server.h
+++ b/test/cpp/util/metrics_server.h
@@ -36,7 +36,6 @@
 #include <atomic>
 #include <map>
 #include <mutex>
-#include <vector>
 
 #include "test/proto/metrics.grpc.pb.h"
 #include "test/proto/metrics.pb.h"
@@ -61,9 +60,8 @@
 namespace grpc {
 namespace testing {
 
-using std::map;
-using std::vector;
-
+// TODO(sreek): Add support for other types of Gauges like Double, String in
+// future
 class Gauge {
  public:
   Gauge(long initial_val);
@@ -86,7 +84,8 @@
   // is already present in the map.
   // NOTE: CreateGauge can be called anytime (i.e before or after calling
   // StartServer).
-  std::shared_ptr<Gauge> CreateGauge(string name, bool& is_present);
+  std::shared_ptr<Gauge> CreateGauge(const grpc::string& name,
+                                     bool* already_present);
 
   std::unique_ptr<grpc::Server> StartServer(int port);