Returning the self type in Mustinherit class - VB.NET - vb.net

Question

I have an abstract class as
Public MustInherit Class GenericClass
Public Sub New(Byval x as Integer)
' Some code here
End Sub
End Class
I inherit this class to another class as follows:
Public Class SpecificClass
Inherits GenericClass
Public Sub New(Byval x as Integer)
MyBase.New(x)
End Sub
End Class
I want to add a Shared Function e.g. magicFunction in such a way that when I use it, it should return an object of type SpecificClass. What should I do?
I want something like this but it is not allowed in VB.NET
Public MustInherit Class GenericClass
Public Sub New(Byval x as Integer)
' Some code here
End Sub
Public Shared Function magicFunction(Byval y as Integer) as GenericClass
Dim z as Integer
' Some code here that will alter the value of z
Return New GenericClass(z) ' Not allowed in VB.NET -- MustInherit class cannot have new
End Sub
End Class
Calling the magicFunction of the inheriting SpecificClass should return an object of SpecificClass like this:
Public Class ABC
Public Function myAwesomeFunction as SpecificClass
Dim objSpecificClass as SpecificClass
objSpecificClass = SpecificClass.magicFunction(someInteger)
Return objSpecificClass
End Sub
End Class
Any help would be appreciated

Answer 1

This may help:
Public MustInherit Class GenericClass(Of T As {GenericClass(Of T)})
Public Sub New(ByVal x As Integer)
' Some code here
End Sub
Public Shared Function magicFunction(ByVal y As Integer) As GenericClass(Of T)
Dim z As Integer
' Some code here that will alter the value of z
Return Activator.CreateInstance(GetType(T), z)
End Function
End Class
Public Class SpecificClass1
Inherits GenericClass(Of SpecificClass1)
Public Sub New(ByVal x As Integer)
MyBase.New(x)
End Sub
End Class
Public Class SpecificClass2
Inherits GenericClass(Of SpecificClass2)
Public Sub New(ByVal x As Integer)
MyBase.New(x)
End Sub
End Class
Usage:
Dim a As SpecificClass1 = SpecificClass1.magicFunction(1)
Dim b As SpecificClass2 = SpecificClass2.magicFunction(2)