Add Design Patterns

ProxyLib/SubjectProxy.cs

@@ -0,0 +1,13 @@
+namespace ProxyLib;
+
+public class SubjectProxy : ISubject
+{
+    public bool CanLog { get; set; }
+    private readonly ISubject _subject = new ConcreteSubject();
+
+    public void Log()
+    {
+        if (!CanLog) return;
+        _subject.Log();
+    }
+}