code: public static Rule getRule(final String field, final String value) {
      if (field.equalsIgnoreCase(LoggingEventFieldResolver.LEVEL_FIELD)) {
          return NotLevelEqualsRule.getRule(value);
      } else {
          return new NotEqualsRule(field, value);
      }
    }
docs: Get new instance.
  @param field field
  @param value value
  @return new instance.