code: protected void updateCompanies(final LoginContext _login,
                                     final Person _person)
          throws EFapsException
      {
          if (!JAASSystem.getAllJAASSystems().isEmpty()) {
              _person.setCompanies(JAASSystem.getAllJAASSystems().iterator().next(), _person.getCompaniesFromDB(null));
          }
      }
docs: The groups of the given person are updated with the information from the
  JAAS login context.
  TODO: no real check or update is done
  @param _login    JAAS login context
  @param _person   person for which the groups must be updated
  @throws EFapsException if a method of the principals inside the JAAS
  login contexts could not be executed or the
  groups for the given person could not be set.