use warnings;
use strict;
use feature 'say';

use Mock::Sub;

$SIG{__WARN__} = sub {say $_[0] if $_[0] !~ /Prototype/};

my $m = Mock::Sub->new;

sub foo ($$$){
    say "hello!"; # doesn't get called
    return undef;
}

my $foo = $m->mock('foo');
$foo->return_value('test');

say foo(1, 2, 3);
say foo(1, 2, 3);
say foo(1, 2, 3);

say $foo->called_count;