Public Function New( _
   ByVal minItems As Integer, _
   ByVal maxItems As Integer, _
   ByVal maxAge As TimeSpan, _
   ByVal externalTicks As Boolean _
)

public ObjectKeepAlive( 
   int minItems,
   int maxItems,
   TimeSpan maxAge,
   bool externalTicks
)

WeakReference r;
TimeSpan timeout = TimeSpan.FromMilliseconds(100);
ObjectKeepAlive keep = new ObjectKeepAlive(1, 10, timeout, false);

if (true)
{
    object target = new MyObject();
    r = new WeakReference(target);
    keep.Add(target);
    target = null;
}

_destroyed = false;
Assert.IsTrue(r.IsAlive);

for (int i = 0; i < 5; i++)
    keep.Add(i);

Assert.IsTrue(r.IsAlive);

GC.GetTotalMemory(true);
GC.WaitForPendingFinalizers();
Assert.IsTrue(r.IsAlive);
Assert.IsFalse(_destroyed);

long start = DateTime.UtcNow.Ticks;
while ((start + timeout.Ticks) > DateTime.UtcNow.Ticks)
    System.Threading.Thread.SpinWait(100);

//Time has elapsed, yet it nothing is added, and Tick() is not called, it remains in memory
GC.GetTotalMemory(true);
GC.WaitForPendingFinalizers();
Assert.IsTrue(r.IsAlive);
Assert.IsFalse(_destroyed);

//Once the collection is touched with either a call to Add or Tick, timeout will expire
keep.Add(new object());

GC.GetTotalMemory(true);
GC.WaitForPendingFinalizers();
Assert.IsFalse(r.IsAlive);
Assert.IsTrue(_destroyed);

Dim r As WeakReference
Dim timeout As TimeSpan = TimeSpan.FromMilliseconds(100)
Dim keep As New ObjectKeepAlive(1, 10, timeout, False)

If True Then
    Dim target As Object = New MyObject()
    r = New WeakReference(target)
    keep.Add(target)
    target = Nothing
End If

_destroyed = False
Assert.IsTrue(r.IsAlive)

Dim i As Integer = 0
While i < 5
    keep.Add(i)
    System.Math.Max(System.Threading.Interlocked.Increment(i),i - 1)
End While

Assert.IsTrue(r.IsAlive)

GC.GetTotalMemory(True)
GC.WaitForPendingFinalizers()
Assert.IsTrue(r.IsAlive)
Assert.IsFalse(_destroyed)

Dim start As Long = DateTime.UtcNow.Ticks
While (start + timeout.Ticks) > DateTime.UtcNow.Ticks
    System.Threading.Thread.SpinWait(100)
End While

'Time has elapsed, yet it nothing is added, and Tick() is not called, it remains in memory
GC.GetTotalMemory(True)
GC.WaitForPendingFinalizers()
Assert.IsTrue(r.IsAlive)
Assert.IsFalse(_destroyed)

'Once the collection is touched with either a call to Add or Tick, timeout will expire
keep.Add(New Object())

GC.GetTotalMemory(True)
GC.WaitForPendingFinalizers()
Assert.IsFalse(r.IsAlive)
Assert.IsTrue(_destroyed)