code: public static void clearBlacklists(ClassLoader loader)
     {
        if (isJBossRepositoryClassLoader(loader))
        {
  			for(Method m : loader.getClass().getMethods())
  			{
  				if("clearBlackLists".equalsIgnoreCase(m.getName()))
  				{
  					try
  					{
  						m.invoke(loader);
  					}
  					catch (Exception e)
  					{
  					    if (ROOT_LOGGER.isTraceEnabled()) ROOT_LOGGER.couldNotClearBlacklist(loader, e);
  					}
  				}
  			}			
        }
     }
docs: Clears black lists on a JBoss RepositoryClassLoader. This is somewhat of a hack, and
  could be replaced with an integration module. This is needed when the following order of
  events occur.
  
  <ol>
  <li>loadClass() returns not found</li>
  <li>Some call to defineClass()</li>
  <ol>
  
  The CNFE triggers a black list addition, which cause the class never again to be found.
  
  @param loader the loader to clear black lists for