diff --git a/lib/experimental/binding.dart b/lib/experimental/binding.dart
index 3ab9beb..6dc0e2a 100644
--- a/lib/experimental/binding.dart
+++ b/lib/experimental/binding.dart
@@ -7,8 +7,8 @@ class Binding<T> {
   late Mode _mode;
   late Type _key;
   late String _name;
-  late T _instance;
-  late T Function() _provider;
+  T? _instance = null;
+  T? Function()? _provider = null;
   late bool _isSingeltone = false;
   late bool _isNamed = false;
 
@@ -84,7 +84,7 @@ class Binding<T> {
   /// return [Binding]
   Binding<T> singeltone() {
     if (_mode == Mode.PROVIDER_INSTANCE) {
-      _instance = _provider.call();
+      _instance = _provider?.call();
     }
     _isSingeltone = true;
     return this;
@@ -100,5 +100,5 @@ class Binding<T> {
   /// ENG: Resolve instance.
   ///
   /// return [T]
-  T? get provider => _provider.call();
+  T? get provider => _provider?.call();
 }
diff --git a/test/experimental/module_test.dart b/test/experimental/module_test.dart
new file mode 100644
index 0000000..db57e7b
--- /dev/null
+++ b/test/experimental/module_test.dart
@@ -0,0 +1,296 @@
+import 'package:dart_di/experimental/binding.dart';
+import 'package:test/test.dart';
+
+void main() {
+  group("Check instance.", () {
+    group("Without name.", () {
+      test("Binding resolves null", () {
+        final binding = Binding<int>();
+        expect(binding.instance, null);
+      });
+
+      test("Binding check mode", () {
+        final expectedValue = 5;
+        final binding = Binding<int>().toInstance(expectedValue);
+
+        expect(binding.mode, Mode.INSTANCE);
+      });
+
+      test("Binding check singeltone", () {
+        final expectedValue = 5;
+        final binding = Binding<int>().toInstance(expectedValue);
+
+        expect(binding.isSingeltone, true);
+      });
+
+      test("Binding check value", () {
+        final expectedValue = 5;
+        final binding = Binding<int>().toInstance(expectedValue);
+
+        expect(binding.instance, expectedValue);
+      });
+
+      test("Binding resolves value", () {
+        final expectedValue = 5;
+        final binding = Binding<int>().toInstance(expectedValue);
+        expect(binding.instance, expectedValue);
+      });
+    });
+
+    group("With name.", () {
+      test("Binding resolves null", () {
+        final binding = Binding<int>().withName("expectedValue");
+        expect(binding.instance, null);
+      });
+
+      test("Binding check mode", () {
+        final expectedValue = 5;
+        final binding =
+            Binding<int>().withName("expectedValue").toInstance(expectedValue);
+
+        expect(binding.mode, Mode.INSTANCE);
+      });
+
+      test("Binding check key", () {
+        final expectedValue = 5;
+        final binding =
+            Binding<int>().withName("expectedValue").toInstance(expectedValue);
+
+        expect(binding.key, int);
+      });
+
+      test("Binding check singeltone", () {
+        final expectedValue = 5;
+        final binding =
+            Binding<int>().withName("expectedValue").toInstance(expectedValue);
+
+        expect(binding.isSingeltone, true);
+      });
+
+      test("Binding check value", () {
+        final expectedValue = 5;
+        final binding =
+            Binding<int>().withName("expectedValue").toInstance(expectedValue);
+
+        expect(binding.instance, expectedValue);
+      });
+
+      test("Binding check value", () {
+        final expectedValue = 5;
+        final binding =
+            Binding<int>().withName("expectedValue").toInstance(expectedValue);
+
+        expect(binding.name, "expectedValue");
+      });
+
+      test("Binding resolves value", () {
+        final expectedValue = 5;
+        final binding =
+            Binding<int>().withName("expectedValue").toInstance(expectedValue);
+        expect(binding.instance, expectedValue);
+      });
+    });
+  });
+
+  group("Check provide.", () {
+    group("Without name.", () {
+      test("Binding resolves null", () {
+        final binding = Binding<int>();
+        expect(binding.provider, null);
+      });
+
+      test("Binding check mode", () {
+        final expectedValue = 5;
+        final binding = Binding<int>().toProvide(() => expectedValue);
+
+        expect(binding.mode, Mode.PROVIDER_INSTANCE);
+      });
+
+      test("Binding check singeltone", () {
+        final expectedValue = 5;
+        final binding = Binding<int>().toProvide(() => expectedValue);
+
+        expect(binding.isSingeltone, false);
+      });
+
+      test("Binding check value", () {
+        final expectedValue = 5;
+        final binding = Binding<int>().toProvide(() => expectedValue);
+
+        expect(binding.provider, expectedValue);
+      });
+
+      test("Binding resolves value", () {
+        final expectedValue = 5;
+        final binding = Binding<int>().toProvide(() => expectedValue);
+        expect(binding.provider, expectedValue);
+      });
+    });
+
+    group("With name.", () {
+      test("Binding resolves null", () {
+        final binding = Binding<int>().withName("expectedValue");
+        expect(binding.provider, null);
+      });
+
+      test("Binding check mode", () {
+        final expectedValue = 5;
+        final binding = Binding<int>()
+            .withName("expectedValue")
+            .toProvide(() => expectedValue);
+
+        expect(binding.mode, Mode.PROVIDER_INSTANCE);
+      });
+
+      test("Binding check key", () {
+        final expectedValue = 5;
+        final binding = Binding<int>()
+            .withName("expectedValue")
+            .toProvide(() => expectedValue);
+
+        expect(binding.key, int);
+      });
+
+      test("Binding check singeltone", () {
+        final expectedValue = 5;
+        final binding = Binding<int>()
+            .withName("expectedValue")
+            .toProvide(() => expectedValue);
+
+        expect(binding.isSingeltone, false);
+      });
+
+      test("Binding check value", () {
+        final expectedValue = 5;
+        final binding = Binding<int>()
+            .withName("expectedValue")
+            .toProvide(() => expectedValue);
+
+        expect(binding.provider, expectedValue);
+      });
+
+      test("Binding check value", () {
+        final expectedValue = 5;
+        final binding = Binding<int>()
+            .withName("expectedValue")
+            .toProvide(() => expectedValue);
+
+        expect(binding.name, "expectedValue");
+      });
+
+      test("Binding resolves value", () {
+        final expectedValue = 5;
+        final binding = Binding<int>()
+            .withName("expectedValue")
+            .toProvide(() => expectedValue);
+        expect(binding.provider, expectedValue);
+      });
+    });
+  });
+
+  group("Check singeltone provide.", () {
+    group("Without name.", () {
+      test("Binding resolves null", () {
+        final binding = Binding<int>().singeltone();
+        expect(binding.provider, null);
+      });
+
+      test("Binding check mode", () {
+        final expectedValue = 5;
+        final binding =
+            Binding<int>().toProvide(() => expectedValue).singeltone();
+
+        expect(binding.mode, Mode.PROVIDER_INSTANCE);
+      });
+
+      test("Binding check singeltone", () {
+        final expectedValue = 5;
+        final binding =
+            Binding<int>().toProvide(() => expectedValue).singeltone();
+
+        expect(binding.isSingeltone, true);
+      });
+
+      test("Binding check value", () {
+        final expectedValue = 5;
+        final binding =
+            Binding<int>().toProvide(() => expectedValue).singeltone();
+
+        expect(binding.provider, expectedValue);
+      });
+
+      test("Binding resolves value", () {
+        final expectedValue = 5;
+        final binding =
+            Binding<int>().toProvide(() => expectedValue).singeltone();
+        expect(binding.provider, expectedValue);
+      });
+    });
+
+    group("With name.", () {
+      test("Binding resolves null", () {
+        final binding = Binding<int>().withName("expectedValue").singeltone();
+        expect(binding.provider, null);
+      });
+
+      test("Binding check mode", () {
+        final expectedValue = 5;
+        final binding = Binding<int>()
+            .withName("expectedValue")
+            .toProvide(() => expectedValue)
+            .singeltone();
+
+        expect(binding.mode, Mode.PROVIDER_INSTANCE);
+      });
+
+      test("Binding check key", () {
+        final expectedValue = 5;
+        final binding = Binding<int>()
+            .withName("expectedValue")
+            .toProvide(() => expectedValue)
+            .singeltone();
+
+        expect(binding.key, int);
+      });
+
+      test("Binding check singeltone", () {
+        final expectedValue = 5;
+        final binding = Binding<int>()
+            .withName("expectedValue")
+            .toProvide(() => expectedValue)
+            .singeltone();
+
+        expect(binding.isSingeltone, true);
+      });
+
+      test("Binding check value", () {
+        final expectedValue = 5;
+        final binding = Binding<int>()
+            .withName("expectedValue")
+            .toProvide(() => expectedValue)
+            .singeltone();
+
+        expect(binding.provider, expectedValue);
+      });
+
+      test("Binding check value", () {
+        final expectedValue = 5;
+        final binding = Binding<int>()
+            .withName("expectedValue")
+            .toProvide(() => expectedValue)
+            .singeltone();
+
+        expect(binding.name, "expectedValue");
+      });
+
+      test("Binding resolves value", () {
+        final expectedValue = 5;
+        final binding = Binding<int>()
+            .withName("expectedValue")
+            .toProvide(() => expectedValue)
+            .singeltone();
+        expect(binding.provider, expectedValue);
+      });
+    });
+  });
+}