code: protected function _ns($id = null, $decamelize = true, $separator = '.') {
          static $decamelizeds = [];
          $me = get_class($this);
          if ($decamelize && empty($decamelizeds[$me])) {
              $decamelizeds[$me] = \decamelize($this->getName());
          }
          $ns = $decamelize ? $decamelizeds[$me] : $this->getName();
          return $ns . ($id ? $separator . $id : '');
      }
docs: Helper function  to prefix ids with the pack name as namespace.
  ie. for a pack named 'MyFooPack', the  id 'bar' becomes 'MyFoo.bar' or 'my_foo.bar' (with decamelize).
  
  @param string $id an id to namespace
  @param boolean $decamelize
  @param string $separator
  @return string the pack namespaced id