package Foo;
use strict;
use warnings;

BEGIN {
  printf "BEGIN called from package %s\n", __PACKAGE__;
}

print "Class level logic.\n";

sub new {
  my $class = shift;
  $class = ref($class) || $class; # subclass boilerplate.
  print "constructor invoked for $class\n";
  return bless {}, $class;
}

1;