try to fix bug

server/src/UdpClientPool.cs

@@ -2,7 +2,7 @@ using System.Net;
 using System.Net.Sockets;
 using System.Text;
 
-class UDPClientPool
+public class UDPClientPool
 {
     private static IPAddress localhost = IPAddress.Parse("127.0.0.1");
 
@@ -13,6 +13,8 @@ class UDPClientPool
         byte[] sendbuf = Encoding.ASCII.GetBytes(stringArray[0]);
 
         var sendLen = socket.SendTo(sendbuf, endPoint);
+        socket.Close();
+
         if (sendLen == stringArray[0].Length) { return true; }
         else { return false; }
     }
@@ -26,6 +28,8 @@ class UDPClientPool
     {
         Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
         var sendLen = socket.SendTo(buf, endPoint);
+        socket.Close();
+
         if (sendLen == buf.Length) { return true; }
         else { return false; }
     }
@@ -40,6 +44,8 @@ class UDPClientPool
         Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
         var sendBytes = pkg.ToBytes();
         var sendLen = socket.SendTo(sendBytes, endPoint);
+        socket.Close();
+
         if (sendLen == sendBytes.Length) { return true; }
         else { return false; }
     }
@@ -54,6 +60,8 @@ class UDPClientPool
         Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
         var sendBytes = pkg.ToBytes();
         var sendLen = socket.SendTo(sendBytes, endPoint);
+        socket.Close();
+
         if (sendLen == sendBytes.Length) { return true; }
         else { return false; }
     }
@@ -71,6 +79,8 @@ class UDPClientPool
         IPEndPoint ep = new IPEndPoint(localhost, port);
 
         var sendLen = socket.SendTo(sendBytes, ep);
+        socket.Close();
+
         if (sendLen == sendBytes.Length) { return true; }
         else { return false; }
     }
@@ -87,5 +97,7 @@ class UDPClientPool
 
             Thread.Sleep(sleepMilliSeconds);
         }
+
+        socket.Close();
     }
 }

server/src/UdpServer.cs

@@ -92,7 +92,7 @@ public class UDPServer
         {
             Console.WriteLine(e.ToString());
             throw new ArgumentException(
-                $"Not currect port num: {port}",
+                $"Failed to set up server with this port: {port}",
                 nameof(port)
                 );
         }
@@ -143,7 +143,7 @@ public class UDPServer
         }
         else
         {
-            return Optional.Some((UDPData)data);
+            return Optional.Some((UDPData)data.DeepClone());
         }
     }
 
@@ -196,7 +196,7 @@ public class UDPServer
         }
         else
         {
-            return Optional.Some((UDPData)data);
+            return Optional.Some((UDPData)data.DeepClone());
         }
     }