Select Code to Download

use Carp;
my %FOO_KNOWN_ARGS = map {$_=>1} qw/ quz baz /;
...
}
foo(quz=>1,baz=>1);
foo(quz=>1,baz=>1,bar=>1); # dies

use Hash::Util qw/lock_ref_keys/;
my $foo = {};
lock_ref_keys($foo, qw/ quz baz /);
$foo->{quz} = 1;
$foo->{bar} = 1; # dies

{   package Foo;
    use Moo;
...
    die "Not a Foo" unless blessed($foo) && $foo->isa('Foo');
    print "baz2, the foo is ",$foo->foo,"\n";
}