Public Sub SetValue( _
   ByVal instance As Object, _
   ByVal value As Object _
) 

public void SetValue( 
   object instance,
   object value
)

a classa = new a();
classa.PropertyA = "hello";
Assert.AreEqual("hello", classa.PropertyA);

PropertyType pt = new PropertyType(classa.GetType(), "PropertyA");
Assert.AreEqual("hello", pt.GetValue(classa));
pt.SetValue(classa, "world");
Assert.AreEqual("world", pt.GetValue(classa));
Assert.AreEqual("world", classa.PropertyA);

classa.PropertyA = "hello";//set privateField back to "hello"
Assert.AreEqual("hello", classa.PropertyA);

pt = new PropertyType(classa.GetType(), "privateField");
Assert.AreEqual("hello", pt.GetValue(classa));
pt.SetValue(classa, "world");
Assert.AreEqual("world", pt.GetValue(classa));
Assert.AreEqual("world", classa.PropertyA);

Dim classa As New a()
classa.PropertyA = "hello"
Assert.AreEqual("hello", classa.PropertyA)

Dim pt As New PropertyType(classa.[GetType](), "PropertyA")
Assert.AreEqual("hello", pt.GetValue(classa))
pt.SetValue(classa, "world")
Assert.AreEqual("world", pt.GetValue(classa))
Assert.AreEqual("world", classa.PropertyA)

classa.PropertyA = "hello"
'set privateField back to "hello"
Assert.AreEqual("hello", classa.PropertyA)

pt = New PropertyType(classa.[GetType](), "privateField")
Assert.AreEqual("hello", pt.GetValue(classa))
pt.SetValue(classa, "world")
Assert.AreEqual("world", pt.GetValue(classa))
Assert.AreEqual("world", classa.PropertyA)