code: public void associateConnection(Object connection) throws ResourceException {
      log.finest("associateConnection()");
  
      if (connection == null)
        throw new ResourceException("Null connection handle");
  
      if (!(connection instanceof VertxConnectionImpl))
        throw new ResourceException("Wrong connection handle");
  
      this.vertxConn = (VertxConnectionImpl) connection;
    }
docs: Used by the container to change the association of an application-level
  connection handle with a ManagedConneciton instance.
  
  @param connection
  Application-level connection handle
  @throws ResourceException
  generic exception if operation fails