code: List<ConnectionListener> getConnectionListeners(ConnectionManager cm)
     {
        if (cmToCl == null)
           return Collections.unmodifiableList(Collections.emptyList());
  
        List<ConnectionListener> l = cmToCl.get(cm);
        if (l == null)
           l = Collections.emptyList();
        
        return Collections.unmodifiableList(l);
     }
docs: Get the connection listeners for a connection manager
  @param cm The connection manager
  @return The value