How to use extender provider in vb.net - vb.net

Question

I have this code I want to use it in my form
how to do it?
Imports System.ComponentModel
'...
<ProvideProperty("NullableTextBox", typeof(TextBox) Is )>
Partial Public Class NullableTextBox
Inherits Component
Implements IExtenderProvider
Dim _nullables As Dictionary(Of Control, Boolean) = New Dictionary(Of Control, Boolean)
''' <summary>
''' This is the get part of the extender property.
''' It is actually a method because it takes the control.
''' </summary>
''' <param name="control"></param>
<DefaultValue(False), _
Category("Data")> _
Public Function GetNullableBinding(ByVal control As Control) As Boolean
Dim nullableBinding As Boolean = False
_nullables.TryGetValue(control, nullableBinding)
Return nullableBinding
End Function
''' <summary>
''' This is the set part of the extender property.
''' It is actually a method because it takes the control.
''' </summary>
''' <param name="control"></param>
''' <param name="nullable"></param>
Public Sub SetNullableBinding(ByVal control As Control, ByVal nullable As Boolean)
If _nullables.ContainsKey(control) Then
_nullables(control) = nullable
Else
_nullables.Add(control, nullable)
End If
If nullable Then
' Add a parse event handler.
AddHandler control.DataBindings("Text").Parse, AddressOf Me.NullableExtender_Parse
End If
End Sub
''' <summary>
''' When parsing, set the value to null if the value is empty.
''' </summary>
''' <param name="sender"></param>
''' <param name="e"></param>
Private Sub NullableExtender_Parse(ByVal sender As Object, ByVal e As ConvertEventArgs)
If (e.Value.ToString.Length = 0) Then
e.Value = Nothing
End If
End Sub
End Class