package WWW::Mechanize::KeepSlim;

our @ISA = qw/WWW::Mechanize/;

sub _push_page_stack {
    my $self = shift;

    if ( $self->{res} ) {
	my $save_stack = $self->{page_stack};
	$self->{page_stack} = [];
	push( @$save_stack, $self->clone );

        # HERE! - stop the stack getting bigger than 10
	if ( @$save_stack > 10 ) {
	    shift(@$save_stack);
	}

	$self->{page_stack} = $save_stack;
    }
    return 1;
}

package main;

my $agent = WWW::Mechanize::KeepSlim->new();

# ....