code: @Override
      public Node getPrincipal() {
          if (principal == null) {
              principal = new LdapUser();
              LdapUser p = (LdapUser) principal;
              p.setDn(Configuration.getProperty(instanceName + ".principal").trim());
              p.setUid(getUidForDN(p.getDn()));
          }
          return principal;
      }
docs: Returns the LDAP-Principal as a LdapUser.
  
  @return the Principal of that instanceName as a Node