public function test_add_behaviour() { $chain = new Chain(); assertThat($chain->find('fred'), is(null)); $chain->add('fred'); assertThat($chain->find('fred'), is('fred')); assertThat($chain->find('wilma'), is(null)); $chain->add('wilma'); assertThat($chain->find('fred'), is('fred')); assertThat($chain->find('wilma'), is('wilma')); assertThat($chain->getTokens(), contains(array('fred', 'wilma'))); }