code: @SuppressWarnings("unchecked")
      public MappedLdapGroup getMappedLdapGroup(final Team team, final String dn) {
          final Query query = pm.newQuery(MappedLdapGroup.class, "team == :team && dn == :dn");
          final List<MappedLdapGroup> result = (List<MappedLdapGroup>) query.execute(team, dn);
          return Collections.isEmpty(result) ? null : result.get(0);
      }
docs: Retrieves a MappedLdapGroup object for the specified Team and LDAP group.
  @param team a Team object
  @param dn a String representation of Distinguished Name
  @return a MappedLdapGroup if found, or null if no mapping exists
  @since 1.4.0