/**
  * Find any host.
  *
  * @param artifact the artifact
  * @return the resource host (possibly null)
  */
 private ResourceHost findAnyPresence(Artifact artifact) {
   synchronized (m_resourceHosts) {
     Iterator list = m_resourceHosts.values().iterator();
     while (list.hasNext()) {
       ResourceHost host = (ResourceHost) list.next();
       if (host.isEnabled()) {
         if (host.checkPresence(artifact, false)) {
           return host;
         }
       }
     }
     return null;
   }
 }