title: Interposer class
body: <p>Do I need to put my Interposer class in
  all the form that will the particular class ?
  Say I want to re-implement TPanel, I redeclare
  it as  <strong><em>TPanel = class(ExtCtrls.TPanel)</em></strong> in the unit.
  Do I need to do this in all the unit that uses
  TPanel ?</p>
  
  <p>Thanks in advance !</p>