static boolean isRegistered(ObjectName objectName) {
    return mbeanServer != null && mbeanServer.isRegistered(objectName);
  }
Returns true if a MBean with given ObjectName is registered.

@param objectName ObjectName to use for checking if MBean is registered
@return true if MBeanServer is not null & MBean with given ObjectName is registered with the
        MBeanServer
geode-core/src/main/java/org/apache/geode/admin/jmx/internal/MBeanUtils.java