diff --git a/cmds/idmap2/libidmap2/Idmap.cpp b/cmds/idmap2/libidmap2/Idmap.cpp
index 1ef3267..49bb7d8 100644
--- a/cmds/idmap2/libidmap2/Idmap.cpp
+++ b/cmds/idmap2/libidmap2/Idmap.cpp
@@ -43,17 +43,23 @@
 
 #define EXTRACT_ENTRY(resid) (0x0000ffff & (resid))
 
-struct MatchingResources {
+class MatchingResources {
+ public:
   void Add(ResourceId target_resid, ResourceId overlay_resid) {
     TypeId target_typeid = EXTRACT_TYPE(target_resid);
-    if (map.find(target_typeid) == map.end()) {
-      map.emplace(target_typeid, std::set<std::pair<ResourceId, ResourceId>>());
+    if (map_.find(target_typeid) == map_.end()) {
+      map_.emplace(target_typeid, std::set<std::pair<ResourceId, ResourceId>>());
     }
-    map[target_typeid].insert(std::make_pair(target_resid, overlay_resid));
+    map_[target_typeid].insert(std::make_pair(target_resid, overlay_resid));
   }
 
+  inline const std::map<TypeId, std::set<std::pair<ResourceId, ResourceId>>>& Map() const {
+    return map_;
+  }
+
+ private:
   // target type id -> set { pair { overlay entry id, overlay entry id } }
-  std::map<TypeId, std::set<std::pair<ResourceId, ResourceId>>> map;
+  std::map<TypeId, std::set<std::pair<ResourceId, ResourceId>>> map_;
 };
 
 static bool WARN_UNUSED Read16(std::istream& stream, uint16_t* out) {
@@ -375,8 +381,8 @@
 
   // encode idmap data
   std::unique_ptr<IdmapData> data(new IdmapData());
-  const auto types_end = matching_resources.map.cend();
-  for (auto ti = matching_resources.map.cbegin(); ti != types_end; ++ti) {
+  const auto types_end = matching_resources.Map().cend();
+  for (auto ti = matching_resources.Map().cbegin(); ti != types_end; ++ti) {
     auto ei = ti->second.cbegin();
     std::unique_ptr<IdmapData::TypeEntry> type(new IdmapData::TypeEntry());
     type->target_type_id_ = EXTRACT_TYPE(ei->first);
diff --git a/cmds/idmap2/tests/BinaryStreamVisitorTests.cpp b/cmds/idmap2/tests/BinaryStreamVisitorTests.cpp
index 8b552dc..7d2e8ee 100644
--- a/cmds/idmap2/tests/BinaryStreamVisitorTests.cpp
+++ b/cmds/idmap2/tests/BinaryStreamVisitorTests.cpp
@@ -29,7 +29,6 @@
 
 #include "TestHelpers.h"
 
-using ::testing::IsNull;
 using ::testing::NotNull;
 
 namespace android {
diff --git a/cmds/idmap2/tests/CommandLineOptionsTests.cpp b/cmds/idmap2/tests/CommandLineOptionsTests.cpp
index b04b256..7d1f56b 100644
--- a/cmds/idmap2/tests/CommandLineOptionsTests.cpp
+++ b/cmds/idmap2/tests/CommandLineOptionsTests.cpp
@@ -38,8 +38,6 @@
 
 #include "TestHelpers.h"
 
-using ::testing::NotNull;
-
 namespace android {
 namespace idmap2 {
 
diff --git a/cmds/idmap2/tests/PrettyPrintVisitorTests.cpp b/cmds/idmap2/tests/PrettyPrintVisitorTests.cpp
index da97792..0c4f493 100644
--- a/cmds/idmap2/tests/PrettyPrintVisitorTests.cpp
+++ b/cmds/idmap2/tests/PrettyPrintVisitorTests.cpp
@@ -29,7 +29,6 @@
 
 #include "TestHelpers.h"
 
-using ::testing::IsNull;
 using ::testing::NotNull;
 
 using android::ApkAssets;
diff --git a/cmds/idmap2/tests/RawPrintVisitorTests.cpp b/cmds/idmap2/tests/RawPrintVisitorTests.cpp
index c28ce2e..6285f21 100644
--- a/cmds/idmap2/tests/RawPrintVisitorTests.cpp
+++ b/cmds/idmap2/tests/RawPrintVisitorTests.cpp
@@ -27,7 +27,6 @@
 
 #include "TestHelpers.h"
 
-using ::testing::IsNull;
 using ::testing::NotNull;
 
 namespace android {