{ package T1;              sub s1 { }                  }
{ package T2; use base T1;                             }
{ package T3; use base T2; sub s1 { shift->SUPER::s1 } }

use Devel::Peek qw( Dump );

{
  warn("T1::s1: ", \&T1::s1, "\n");
  warn("T2::s1 (pre):\n"); Dump(*T2::s1);
  T3->s1;
  warn("T2::s1 (post):\n"); Dump(*T2::s1);
}