package TestNew 0.001;

use Moose;

has thingy => (
    required => 1,
    is       => 'ro',
);

my %obj_cache;

override 'new' => sub {
    my ( $class, @args ) = @_;
    my $params   = $class->BUILDARGS(@args); # from Moose::Object
    my $thingy   = $params->{thingy};
    my $cachekey = $thingy;
    if ( exists $obj_cache{$cachekey} ) {
        return $obj_cache{$cachekey};
    }
    return $obj_cache{$thingy} = $class->_new( thingy => $thingy );
};

*Moose::Object::_new = \&Moose::Object::new;

__PACKAGE__->meta->make_immutable( constructor_name => '_new' );

1;