An example of a more complicated Moose attribute declaration

gistfile1.PL

use MP::MS5::Types qw[ClientType];

has _client_types => (
    is      => 'rw',
    default => sub { [] },
    coerce  => 1,
    isa     => ClientTypes,
    traits  => [qw(Array)],
    handles => {
        register     => 'push',
        client_types => 'elements',
    },
);