code: protected void registerJavaTimeDatatypes() {
  
      // prevent compile-time dependencies and GWT availability problems
      registerStandardDatatype("java.time.LocalTime");
      registerStandardDatatype("java.time.LocalDate");
      registerStandardDatatype("java.time.LocalDateTime");
      registerStandardDatatype("java.time.MonthDay");
      registerStandardDatatype("java.time.Year");
      registerStandardDatatype("java.time.YearMonth");
      registerStandardDatatype("java.time.Instant");
      registerStandardDatatype("java.time.Duration");
      registerStandardDatatype("java.time.Period");
      registerStandardDatatype("java.time.OffsetTime");
      registerStandardDatatype("java.time.OffsetDate");
      registerStandardDatatype("java.time.OffsetDateTime");
      registerStandardDatatype("java.time.ZoneId");
      registerStandardDatatype("java.time.ZonedDateTime");
      registerStandardDatatype("java.time.ZoneOffset");
      registerStandardDatatype("java.time.ZoneRegion");
    }
docs: Called from {@link #registerDefaultDatatypes()} to add JSR310 datatypes. Can also be called standalone or
  overridden for customization.