docs: @Override
      @FFDCIgnore(com.ibm.websphere.security.EntryNotFoundException.class)
      public String getUserSecurityName(String uniqueUserId) throws EntryNotFoundException, RegistryException {
          try {
              return customUserRegistry.getUserSecurityName(uniqueUserId);
          } catch (com.ibm.websphere.security.EntryNotFoundException e) {
              throw new EntryNotFoundException(e.getMessage(), e);
          } catch (Exception e) {
              throw new RegistryException(e.getMessage(), e);
          }
      }