/**
* Returns whether this placemark must retrieve its model resource. This always returns <code>
* false</code> if this placemark has no <code>KMLLink</code>.
*
* @return <code>true</code> if this placemark must retrieve its model resource, otherwise <code>
* false</code>.
*/
protected boolean mustRetrieveResource() {
KMLLink link = this.model.getLink();
if (link == null) return false;
// The resource must be retrieved if the link has been updated since the resource was
// last retrieved, or if the resource has never been retrieved.
return this.getColladaRoot() == null || link.getUpdateTime() > this.resourceRetrievalTime.get();
}
