C#, Nunit framework--UML

I have the  class below--UserInfo. I need to use the NUnit Framework to test my class (the web-site www.nunit.org).

1. Am I using NUnit Framework correctly??
2. How can I perform 4th test b1==null ??
3. Am I performing test 1, 2,3, 5.6, 7 correctly??
Thanks

using System;
using System.Collections;
using System.Runtime.Serialization;
using NUnit.Framework;


namespace abc
{
      /// <summary>
      /// Summary
      /// </summary>

      [Serializable()]
      public class UserInfo
      {
            private String _name;      //              
            private String _userId;      //             

            public String Name            
            {                  
                  get { return _name; }                  
                  set { _name = value; }            
            }             


            public String UserId            
            {                  
                  get { return _userId; }                  
                  set { _userId = value; }            
            }             
            /// <summary>            
            /// Default constructor necessary for             
            /// XML serialization            
            /// </summary>
            public UserInfo()            
            {                  
                  _name = String.Empty;                  
                  _userId = String.Empty;            
            }             

            public UserInfo(String name, String userId)            
            {                  
                  this._name = name;                  
                  this._userId = userId;            
            }             
   
            public override bool Equals(object obj)            
            {                  
                  if ((object)obj == null)                        
                        return false;                   

                  if(!(obj is UserInfo))                        
                        return false;                   

                  return (this._name == (obj as UserInfo)._name) && (_userId == (obj as UserInfo)._userId);            
            }             

            public override string ToString()            
            {                  
                  return String.Format("{0}: {1}", _userId, _name);            
            }             


            public override int GetHashCode()            
            {                  
                  return this.ToString().GetHashCode();            
            }      

      }

      // Start Nunit HERE

      

      [TestFixture]
      public class TestCase
      {
       UserInfo b1;
         UserInfo b2;
         UserInfo b3;
         UserInfo b4;

            [SetUp]
            public void Init()
            {
           b1 = new UserInfo("Bill Smith", "BSMITH");
               b2 = new UserInfo("Bill Smith", "BSMITH");
               
               b3 = new UserInfo("Susan Smith", "SSMITH");
               b4 = new UserInfo(null,null);

               string str="Some String"; // for test #5

                  Hashtable ht = new Hashtable(); //test #7
                  ht.Add(b1,"Some Data");
                  String s = (String) ht[b1];
            }

            [Test]
            public void CompareObj()
            {
                // Test b1==b1  /1st test
                  System.Console.WriteLine( b1.Equals(b1) ); // prints true
                  Assert.AreEqual("Bill Smith",b1.Name);
            Assert.AreEqual("BSMITH",b1.UserId);

                  // 2nd Test b1==b2
                  System.Console.WriteLine( b1.Equals(b2) ); // prints true
            Assert.AreEqual("Bill Smith",b1.Name);
                  Assert.AreEqual("Bill Smith",b2.Name);

            Assert.AreEqual("BSMITH",b1.UserId);
                  Assert.AreEqual("BSMITH",b2.UserId);
      
                  //3rd Test b1==b3
                  System.Console.WriteLine( b1.Equals(b3) ); // prints false
                  Assert.AreEqual("Bill Smith",b1.Name);
                  Assert.AreEqual("Bill Smith",b3.Name);

                  Assert.AreEqual("BSMITH",b1.UserId);
                  Assert.AreEqual("BSMITH",b3.UserId);

                  // 4th test b1==null
                  System.Console.WriteLine( b1.Equals(null) ); // prints false
                  // How can I test it using nunit???
            


                  // 5th test b1=="Some String"
                  System.Console.WriteLine( b1.Equals("Some String") );
            Assert.AreEqual(false,(str is UserInfo)); // Is it correct???

                  // 6th test b4==b1
                  System.Console.WriteLine( b4.Equals(b1) ); // prints false
                  Assert.AreEqual(null,b4.Name); // Is it correct???
                  Assert.AreEqual(null,b1.Name);

                  Assert.AreEqual(null,b4.UserId); // Is it correct???
                  Assert.AreEqual(null,b1.UserId);

                  // 7th test
            System.Console.WriteLine( s.Equals("Some Data") ); // prints true
            Assert.AreEqual("Some Data",s); // Is it correct???
            }
      
      } // End class TestCase
      
      // End Nunit HERE
      
} //End Namespace

Start Free Trial