diff --git a/MiniEngine_Test.cpp b/MiniEngine_Test.cpp
index 9e9db92..f95f1a5 100644
--- a/MiniEngine_Test.cpp
+++ b/MiniEngine_Test.cpp
@@ -31,11 +31,36 @@ std::string GetMD5(unsigned char* buffer,unsigned int bufferLen)
     return str;
 }
 
-int CompareSurface(const Surface& surface1, const Surface& surface2, int allowableError)
+/// Compare two surfaces. Currently, Surface::getRawPointer() does not has constant attribute.
+int CompareSurface(Surface& surface1, Surface& surface2, int allowableError)
 {
     return SDLTest_CompareSurfaces(surface1.getRawPointer(),surface2.getRawPointer(),allowableError);
 }
 
+//private
+struct UniRandom::_impl
+{
+    SDLTest_RandomContext context;
+};
+
+UniRandom::UniRandom()
+{
+    _sp.reset(new _impl);
+    SDLTest_RandomInitTime(&(_sp.get()->context));
+}
+
+UniRandom::UniRandom(unsigned int A, unsigned int B)
+{
+    _sp.reset(new _impl);
+    SDLTest_RandomInit(&(_sp.get()->context),A,B);
+}
+
+uint32_t UniRandom::get()
+{
+    return SDLTest_Random(&(_sp.get()->context));
+}
+
+
 }/// End of namespace MiniEngine::Test
 
 }/// End of namespace MiniEngine
diff --git a/MiniEngine_Test.h b/MiniEngine_Test.h
index 3d6389a..2b71089 100644
--- a/MiniEngine_Test.h
+++ b/MiniEngine_Test.h
@@ -12,6 +12,18 @@ std::string GetMD5(unsigned char* buffer,unsigned int bufferLen);
 void GetMD5Raw(unsigned char* buffer,unsigned int bufferLen,unsigned char* outbuff);
 int CompareSurface(const Surface& surface1,const Surface& surface2,int allowableError);
 
+class UniRandom
+{
+public:
+    /// Default Constructor is based on system current time.
+    UniRandom();
+    UniRandom(unsigned int A,unsigned int B);
+    uint32_t get();
+private:
+    struct _impl;
+    std::shared_ptr<_impl> _sp;
+};
+
 }/// End of namespace MiniEngine::Test
 
 }/// End of namespace MiniEngine