public function testFilters()
 {
     $this->emitter->filter('the_content', function ($content, $append) {
         return $content . ' ' . $append;
     });
     $this->emitter->filter('the_content', function ($content) {
         return $content . ' yolo';
     });
     $content = $this->emitter->applyFilters('the_content', 'ham', 'sandwich');
     $this->assertEquals('ham sandwich yolo', $content);
 }
 public function testHasFilterReturnsTrueWhenFilterAdded()
 {
     $this->emitter->filter('foo', 'strtoupper');
     $hasFilter = $this->emitter->hasFilter('foo');
     $this->assertTrue($hasFilter);
 }