Comparing Collections of Type BusinessCollectionBase

public class Person : BusinessBase
{
  public override int Id { get; set; }
  
  [NotNullOrEmpty(Message = "First name is required.")]
  public string FirstName { get; set; }

  [NotNullOrEmpty(Message = "Last name is required.")]
  public string LastName { get; set; }

  [NotNullOrEmpty(Message = "Email address is required.")]
  [ValidEmail(Message = "A valid e-mail address is required.")]
  public string EmailAddress { get; set; }

  [ValidRange(Message = "Age must be between 0 and 150.", Min = 0, Max = 150)]
  public int Age { get; set; }
}

public class People : BusinessCollectionBase<Person> {}

...

[TestClass]
public class PersonTests
{
  [TestMethod]
  public void PeopleCanBeCompared()
  {
    Person myPerson1 = new Person { FirstName = "Imar", LastName = "Spaanjaars" };
    Person myPerson2 = new Person { FirstName = "Imar", LastName = "Spaanjaars" };
    Assert.IsTrue(myPerson1.Equals(myPerson2));
  }
}

#region IEquatable

/// <summary>
/// Determines if two objects have the same values in all their
/// public properties and fields.
/// </summary>
public bool Equals(BusinessBase other)
{
  if (other == null) return base.Equals(other);

  // Make sure both classes are of the same type
  Type _t = this.GetType();
  if (!other.GetType().Equals(_t)) return false;

  // Compare all properties and ensure they're the same
  PropertyInfo[] props = _t.GetProperties();
  for (int i = 0; i < props.Length; i++)
  {
    object value1 = props[i].GetValue(this, new object[] { });
    object value2 = props[i].GetValue(other, new object[] { });
    // If both are null, or both are the same instance, skip to the next
    // iteration.
    if (ReferenceEquals(value1, null) && ReferenceEquals(value2, null))
    {
      continue;
    }

    // If one is null, but not both, return false.
    if (ReferenceEquals(value1, null) || ReferenceEquals(value2, null))
    {
      return false;
    }

    // If none are null, compare values.
    if (!value1.Equals(value2))
    {
      return false;
    }
  }
  // Got this far - they must be identical!
  return true;
}

public override bool Equals(Object obj)
{
  if (obj == null) return base.Equals(obj);

  if (!(obj is BusinessBase))
    throw new InvalidCastException(@"The 'obj' argument is 
                       not a BusinessBase object.");
  else
    return Equals(obj as BusinessBase);
}

public override int GetHashCode()
{
  int FinalHashCode = 17;
  int OtherCoPrimeNumber = 37;
  Type _t = this.GetType();
  
  // Compare all properties and ensure they're the same
  PropertyInfo[] props = _t.GetProperties();
  for (int i = 0; i < props.Length; i++)
  {
    object value1 = props[i].GetValue(this, new object[] { });
    // If value is null, skip to the next iteration.
    if (value1 != null)
    {
      FinalHashCode = FinalHashCode * OtherCoPrimeNumber + value1.GetHashCode();
    }
  }
  return FinalHashCode;
}

public static bool operator ==(BusinessBase a, BusinessBase b)
{
  // If both are null, or both are the same instance, return true.
  if (ReferenceEquals(a, null) && ReferenceEquals(b, null))
  {
    return true;
  }

  // If one is null, but not both, return false.
  if (ReferenceEquals(a, null) || ReferenceEquals(b, null))
  {
    return false;
  }
  // If neither is null, call the Equals method to compare properties.
  return a.Equals(b);
}

public static bool operator !=(BusinessBase a, BusinessBase b)
{
  return !(a == b);
} 
#endregion

[TestMethod]
public void CollectionsOfPeopleCanBeCompared()
{
  People people1 = new People();
  People people2 = new People();

  Person myPerson1 = new Person { FirstName = "Imar", LastName = "Spaanjaars" };
  people1.Add(myPerson1);

  Person myPerson2 = new Person { FirstName = "Amanda", LastName = "Myer" };
  people1.Add(myPerson2);

  Person myPerson3 = new Person { FirstName = "Imar", LastName = "Spaanjaars" };
  people2.Add(myPerson3);

  Person myPerson4 = new Person { FirstName = "Amanda", LastName = "Myer" };
  people2.Add(myPerson4);

  Assert.IsTrue(people1.Equals(people2));
}

[TestMethod]
public void CollectionsOfPeopleCanBeComparedRegardlessTheOrderOfItemsInTheCollection()
{
  People people1 = new People();
  People people2 = new People();

  Person myPerson1 = new Person { FirstName = "Imar", LastName = "Spaanjaars" };
  people1.Add(myPerson1);

  Person myPerson2 = new Person { FirstName = "Amanda", LastName = "Myer" };
  people1.Add(myPerson2);

  Person myPerson4 = new Person { FirstName = "Amanda", LastName = "Myer" };
  people2.Add(myPerson4);

  Person myPerson3 = new Person { FirstName = "Imar", LastName = "Spaanjaars" };
  people2.Add(myPerson3);

  Assert.IsTrue(people1.Equals(people2));
}