code: public static Long getLong(final LdapEntry entry, final String attribute, final Long nullValue) {
          val v = getString(entry, attribute, nullValue.toString());
          if (NumberUtils.isCreatable(v)) {
              return Long.valueOf(v);
          }
          return nullValue;
      }
docs: Reads a Long value from the LdapEntry.
  
  @param entry     the ldap entry
  @param attribute the attribute name
  @param nullValue the value which should be returning in case of a null value
  @return the long value