#8092 Remove unused singleton classes

Author: skoshelev

src/Libraries/Nop.Core/Infrastructure/SingletonDictionary.cs

@@ -24,34 +24,4 @@ public void SingletonsShareSameSingletonsDictionary()
         BaseSingleton.AllSingletons[typeof(int)].Should().Be(1);
         BaseSingleton.AllSingletons[typeof(double)].Should().Be(2.0M);
     }
-
-    [Test]
-    public void SingletonDictionaryIsCreatedByDefault()
-    {
-        var instance = SingletonDictionary<SingletonTests, object>.Instance;
-        instance.Should().NotBeNull();
-    }
-
-    [Test]
-    public void SingletonDictionaryCanStoreStuff()
-    {
-        var instance = SingletonDictionary<Type, SingletonTests>.Instance;
-        instance[typeof(SingletonTests)] = this;
-        instance[typeof(SingletonTests)].Should().BeSameAs(this);
-    }
-
-    [Test]
-    public void SingletonListIsCreatedByDefault()
-    {
-        var instance = SingletonList<SingletonTests>.Instance;
-        instance.Should().NotBeNull();
-    }
-
-    [Test]
-    public void SingletonListCanStoreItems()
-    {
-        var instance = SingletonList<SingletonTests>.Instance;
-        instance.Insert(0, this);
-        instance[0].Should().BeSameAs(this);
-    }
 }