code: public function subscribe($events)
  	{
  		$events->listen('Neonbug\\Common\\Events\\AdminAddEditPrepareField', function($event) {
  			if ($event->field['type'] != 'user_admin::add_fields.role') return;
  			
  			$roles = \Neonbug\Common\Models\Role::all();
  			$roles_by_key = [];
  			foreach ($roles as $role)
  			{
  				if ($role->id_role == 'admin') continue;
  				$roles_by_key[$role->id_role] = $role->name;
  			}
  			
  			$event->field['values'] = $roles_by_key;
  			
  			$selected_roles = [];
  			if ($event->item != null)
  			{
  				foreach ($event->item->roles as $role)
  				{
  					$selected_roles[] = $role->id_role;
  				}
  			}
  			$event->field['selected_roles'] = $selected_roles;
  		});
  	}
docs: Register the listeners for the subscriber.
  
  @param  Illuminate\Events\Dispatcher  $events
  @return void