#!/usr/bin/perl
use warnings;
use strict;

{   package Known;
    sub new { bless {}, shift }
}
{   package NotOO;
    my $m1 = new Known ();
    my $m2 = new Unknown ();
}
{   package OO;
    sub new { bless {}, shift }
    my $m1 = new Known ();
    my $m2 = new Unknown (); # Undefined subroutine &OO:Unknown called
}
{   package Unknown;
    sub new { bless {}, shift }
}