diff --git a/Composite/Class/ILightNode.cs b/Composite/Class/ILightNode.cs
index 16366f4..3c4f03b 100644
--- a/Composite/Class/ILightNode.cs
+++ b/Composite/Class/ILightNode.cs
@@ -9,11 +9,13 @@ namespace Composite.Class
     public interface ILightNode
     {
         public string InnerHTML(int level = 0);
-        public string OuterHTML(int level =0);
+        public string OuterHTML(int level = 0);
         public void AppendChild(ILightNode node);
         public void ReplaceChild(ILightNode oldNode, ILightNode newNode);
         public void RemoveChild(ILightNode node);
         public void InsertBefore(ILightNode node, ILightNode refNode);
         public ILightNode Clone();
+        public string ToString();
+        
     }
 }
diff --git a/Composite/Class/LightElementNode.cs b/Composite/Class/LightElementNode.cs
index 1a11f58..5dd2275 100644
--- a/Composite/Class/LightElementNode.cs
+++ b/Composite/Class/LightElementNode.cs
@@ -104,5 +104,9 @@ public string OuterHTML(int level)
                 return $"<{LightName}{classAttr}{singleAttr}>";
             }
         }
+        public override string ToString()
+        {
+            return LightName;
+        }
     }
 }
diff --git a/Composite/Class/LightTextNode.cs b/Composite/Class/LightTextNode.cs
index 0389d8a..4cd5e52 100644
--- a/Composite/Class/LightTextNode.cs
+++ b/Composite/Class/LightTextNode.cs
@@ -50,5 +50,9 @@ public void ReplaceChild(ILightNode oldNode, ILightNode newNode)
         {
             
         }
+        public override string ToString()
+        {
+            return LightName;
+        }
     }
 }
diff --git a/Composite/Observer/ChildObserver.cs b/Composite/Observer/ChildObserver.cs
new file mode 100644
index 0000000..870c37a
--- /dev/null
+++ b/Composite/Observer/ChildObserver.cs
@@ -0,0 +1,18 @@
+using Composite.Class;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Composite.Observer
+{
+    public class ChildObserver : IObserver
+    {
+        public void Notify(object sender)
+        {
+            sender = (ILightNode)sender;
+            Console.WriteLine($"Child nodes of {sender} would be displayed here.");
+        }
+    }
+}
diff --git a/Composite/Observer/HandlerContainer.cs b/Composite/Observer/HandlerContainer.cs
new file mode 100644
index 0000000..ea78ccb
--- /dev/null
+++ b/Composite/Observer/HandlerContainer.cs
@@ -0,0 +1,66 @@
+using Composite.Class;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Reflection;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Composite.Observer
+{
+    public enum NodeEvents
+    {
+        mouseIn,
+        mouseOut,
+        click
+    }
+    public class HandlerContainer
+    {
+        //maybe it would be better to add callback functions instead of adding observers to dictionary
+        private Dictionary<ILightNode, Dictionary<NodeEvents, List<IObserver>>> _listeners = 
+                        new Dictionary<ILightNode, Dictionary<NodeEvents, List<IObserver>>>();
+
+        public void AddEventHandler(ILightNode sender, NodeEvents nodeEvent, IObserver handler)
+        {
+            addNode(sender);
+            addHandler(sender, nodeEvent, handler);
+        }
+        //check if node is in list
+        private void addNode(ILightNode node)
+        {            
+            if(!_listeners.ContainsKey(node))
+                _listeners[node] = new Dictionary<NodeEvents, List<IObserver>>();
+        }
+        //add handler
+        private void addHandler(ILightNode node,NodeEvents nodeEvent, IObserver handler)
+        {
+            //check if node has event otherwise create it and add handler
+            if (!_listeners[node].ContainsKey(nodeEvent))
+            {
+                _listeners[node][nodeEvent] = new List<IObserver>() {handler};
+            }
+            else
+            {
+                if (_listeners[node][nodeEvent].IndexOf(handler) == -1)
+                {
+                    _listeners[node][nodeEvent].Add(handler);
+                }
+            }
+
+        }
+
+        public void NotifyHandlers(ILightNode node, NodeEvents nodeEvent)
+        {
+            //idk how to make it readable
+            var observers = _listeners.ContainsKey(node)?
+                            _listeners[node].ContainsKey(nodeEvent)? _listeners[node][nodeEvent] : null 
+                            : null;
+            if (observers == null)
+                return;
+            foreach(var obj in observers)
+            {
+                obj.Notify(node);
+            }
+        }
+    }
+}
diff --git a/Composite/Observer/IObserver.cs b/Composite/Observer/IObserver.cs
new file mode 100644
index 0000000..671cfbe
--- /dev/null
+++ b/Composite/Observer/IObserver.cs
@@ -0,0 +1,13 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Composite.Observer
+{
+    public interface IObserver
+    {
+        public void Notify(object sender);
+    }
+}
diff --git a/Composite/Observer/RandomObserver.cs b/Composite/Observer/RandomObserver.cs
new file mode 100644
index 0000000..c90522c
--- /dev/null
+++ b/Composite/Observer/RandomObserver.cs
@@ -0,0 +1,18 @@
+using Composite.Class;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Composite.Observer
+{
+    public class RandomObserver : IObserver
+    {
+        public void Notify(object sender)
+        {
+            sender = sender as ILightNode;
+            Console.WriteLine($"Random {sender} handler");            
+        }
+    }
+}
diff --git a/Composite/Program.cs b/Composite/Program.cs
index 22cbd64..ed235d3 100644
--- a/Composite/Program.cs
+++ b/Composite/Program.cs
@@ -1,6 +1,20 @@
 using Composite.Class;
+using Composite.Observer;
+
+var container = new HandlerContainer();
 
 ILightNode parent = new LightElementNode("div", "block", false);
+
+container.AddEventHandler(parent, NodeEvents.click, new ChildObserver());
+container.AddEventHandler(parent, NodeEvents.mouseIn, new RandomObserver());
+
+container.NotifyHandlers(parent, NodeEvents.click);
+container.NotifyHandlers(parent, NodeEvents.mouseIn);
+
+Console.ReadLine();
+
+return;
+
 ILightNode table = new LightElementNode("table", "block", false);
 ILightNode tr = new LightElementNode("tr", "inline", false);
 ILightNode td = new LightElementNode("td", "inline", false);