Find and FindAll in generic collections

In .NET 2.0, searching through generic collections such as Arrays and Lists are easier with the new Find and FindAll methods. Both methods accepts a Predicate parameter, which is a delegate to a method. According to MSDN, these methods run in O(n). In situations like searching for item(s) in a collection, I used to write utility functions with simple bubble sort algorithm. This causes code duplication and O(n^2) is just too slow.

Therefore, I wrote couple of test cases to explore these two new methods. Check it out!
TestFixtureSetUp

[TestFixture]
public class TestFindInICollection
{
private List _numbers;
private const int TOTAL_NUMBER = 20;
private const int MAX = 100;
private DomainModel[] _models;

[TestFixtureSetUp]
public void TestFixtureSetUp()
{
_numbers = new List();
_models = new DomainModel[TOTAL_NUMBER];

Random r = new Random();
Console.WriteLine("Orignal Collection");
Console.WriteLine("Size = " + TOTAL_NUMBER);

//populate the number list with pseudo-random numbers
//populate the model list
for (int i = 0; i < TOTAL_NUMBER; i++)
{
int radNum = r.Next(MAX);
_numbers.Add(radNum);
Console.WriteLine(radNum);
_models[i] = new DomainModel(i, DateTime.Now.ToLongTimeString());
}
}

...


Find numbers smaller then 50 using anonymous delegate

[Test]
public void CanFindAllNumbersUsingAnonymousMethod()
{
//_number is prepopulated with 20 random numbers from 0 to 50
//find numbers smaller then 50
List smallerPartition = _numbers.FindAll(delegate(int testInt) { return testInt < 50; });
Console.WriteLine("Numbers smaller then 50");
Console.WriteLine("Size = " + smallerPartition.Count);

foreach (int n in smallerPartition)
{
Assert.IsTrue(n < 50);
Console.WriteLine(n);
}
}


Find the domain model with id equals to 10

[Test]
public void CanFindModelUsingAnonymousMethod()
{
int id = 10;
DomainModel model = Array.Find(_models, delegate(DomainModel testModel) { return testModel.Id == id; });
Assert.AreEqual(10, model.Id);
Console.WriteLine(model);
}


Find numbers larger then 50 by calling a helper function that returns a Predicate

[Test]
public void CanFindAllNumbersUsingFunction()
{
//find numbers bigger then 50
List biggerPartition = _numbers.FindAll(BiggerThen(50));
Console.WriteLine("Numbers bigger then 50");
Console.WriteLine("Size = " + biggerPartition.Count);

foreach (int n in biggerPartition)
{
Assert.IsTrue(n > 50);
Console.WriteLine(n);
}
}

private Predicate BiggerThen(int p)
{
return delegate(int testInt) { return testInt > p; };
}


Simple DomainModel Class

class DomainModel
{
private int _id;
private string _label;

public DomainModel(int id, string label)
{
_id = id;
_label = label;
}

public int Id
{
get { return _id; }
set { _id = value; }
}


public string Label
{
get { return _label; }
set { _label = value; }
}

public override string ToString()
{
return _id + " " + _label;
}
}

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