{"action":"opened","issue":{"url":"https://api.github.com/repos/dicksont/es6-set-eq/issues/2","repository_url":"https://api.github.com/repos/dicksont/es6-set-eq","labels_url":"https://api.github.com/repos/dicksont/es6-set-eq/issues/2/labels{/name}","comments_url":"https://api.github.com/repos/dicksont/es6-set-eq/issues/2/comments","events_url":"https://api.github.com/repos/dicksont/es6-set-eq/issues/2/events","html_url":"https://github.com/dicksont/es6-set-eq/issues/2","id":131491946,"number":2,"title":"always returns 'Set comparison attempted with a non-set' for me","user":{"login":"theholla","id":10987970,"avatar_url":"https://avatars.githubusercontent.com/u/10987970?v=3","gravatar_id":"","url":"https://api.github.com/users/theholla","html_url":"https://github.com/theholla","followers_url":"https://api.github.com/users/theholla/followers","following_url":"https://api.github.com/users/theholla/following{/other_user}","gists_url":"https://api.github.com/users/theholla/gists{/gist_id}","starred_url":"https://api.github.com/users/theholla/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/theholla/subscriptions","organizations_url":"https://api.github.com/users/theholla/orgs","repos_url":"https://api.github.com/users/theholla/repos","events_url":"https://api.github.com/users/theholla/events{/privacy}","received_events_url":"https://api.github.com/users/theholla/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":0,"created_at":"2016-02-04T22:27:50Z","updated_at":"2016-02-04T22:27:50Z","closed_at":null,"body":"This package doesn't work as expected when installed on my machine. Even if 'a' and 'b' are an `instanceof` Set, it will throw the `Set comparison attempted with a non-set` error. When I copy your exact function and place it locally in my project (without installation), it returns `true` or `false` as expected.\r\n\r\nI have declared setEquals in my file like you described (`var setEq = require('es6-set-eq');`) and added it to my project's dependencies. This may just be a configuration problem on my machine, but I thought I'd let you know.\r\n\r\nversions: Node 5.1.0, NPM 3.3.12, ES6"}}