use strict;

{
  package Foo;
  sub terfuge {
    die "DON'T YOU BE CALLIN' THIS HERE METHOD, DANG IT!!!\n"
      unless __FILE__ . __PACKAGE__ eq join '', ( caller )[ 1, 0 ];
    my $self = shift;
    print "From $self: @_\n"
  };
  sub public {
    my $self = shift;
    $self->terfuge( @_ );
  }
}

1;