code: public static String getGroupName(String containerName) {
  
      checkSyntax(containerName);
  
      // If it's a container and it's not a role or a qualified role, then
      // it's a group!
  
      if (!isRole(containerName) && !isQualifiedRole(containerName))
        return containerName;
  
      Matcher m = fqanPattern.matcher(containerName);
  
      if (m.matches()) {
        String groupName = m.group(2);
  
        if (groupName.endsWith("/"))
          return groupName.substring(0, groupName.length() - 1);
        else
          return groupName;
      }
  
      return null;
    }
docs: This method extracts group name information from the FQAN passed as
  argument.
  
  @param containerName
  the FQAN
  @return <ul>
  <li>A string containing the group name, if found</li>
  <li>null, if no group information is contained in the FQAN passed
  as argument
  </ul>