code: public String getOuForNode(final LdapNode node) {
      	if(node == null) {
      		return null;
      	}
          if (node instanceof LdapGroup) {
              String ouGroup = Configuration.getProperty(instanceName + ".ou_group");
              return String.format(LdapKeys.GROUP_CN_FORMAT, groupIdentifyer, node.get(groupIdentifyer), ouGroup);
          }
          if (node instanceof LdapUser) {
              String ouPeople = Configuration.getProperty(instanceName + LdapKeys.ATTR_OU_PEOPLE);
              return String.format(LdapKeys.USER_UID_FORMAT, userIdentifyer, node.get(userIdentifyer), ouPeople);
          }
          return String.format(LdapKeys.ENTRY_CN_FORMAT, groupIdentifyer, node.get(groupIdentifyer), node.get(LdapKeys.OWNER));
  
      }
docs: Returns the OU (Organisation-Unit) an Node.
  
  @param node the given node.
  @return the DN of the OU of that node.