Cleaner implementation of `isPresent`
Cleaner implementation of `isPresent`

Co-authored-by: Chris Krycho <aaf4c61ddcc5e8a2dabede0f3b482cd9aea9434d@chriskrycho.com>
sly7-7/ember.js,tildeio/ember.js,emberjs/ember.js,sly7-7/ember.js,sly7-7/ember.js,tildeio/ember.js,emberjs/ember.js,tildeio/ember.js,emberjs/ember.js