Check if class is 'views_content_plugin_display_panel_pane' ignores classes that extend it

Hi,
I tried creating a custom display plugin for views, that would be treated like a view panels pane. So I extended views_content_plugin_display_panel_pane, I was able to get my plugin working, but panels did not treat it like view pane rather a regular view display. I tracked it down to this line of

function _views_content_panes_content_type($view, $display) {
  // Ensure the handler is the right type, as Views will fall back to
  // the default display if something is broken:
 if (get_class($display->handler) != 'views_content_plugin_display_panel_pane') {
    return;
  }

Changing that to

function _views_content_panes_content_type($view, $display) {
  // Ensure the handler is the right type, as Views will fall back to
  // the default display if something is broken:
  if (!is_a($display->handler, 'views_content_plugin_display_panel_pane')) {
    return;
  }

Allowed my new plugin to be treated like view pane.