public void Button1_Click(...)
{
      Progress.Show(0, 100);
          
      Progress.AllocateRangeForCallee(0,25);    //child updates would be mapped to range 0 to 25
      Callee1();  //Callee would also attempt to show progress dialog too

      Progress.Unload();      //ref count =0, this will actually unload
}

private void Callee1()
{
      //this won't re-show, just increment the ref count
      Progress.Show(0, 100);  //this range is mapped to what caller has allocated

      ...         //do work and update progress

      Progress.Unload();  // this won't actually unload, just decrement the ref count
}