code: @Override
      public long getLong(TemporalField field) {
          if (field == WEEK_BASED_YEAR) {
              return year;
          }
          if (field == WEEK_OF_WEEK_BASED_YEAR) {
              return week;
          }
          if (field instanceof ChronoField) {
              throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
          }
          return field.getFrom(this);
      }
docs: Gets the value of the specified field from this year-week as a {@code long}.
  <p>
  This queries this year-week for the value for the specified field.
  If it is not possible to return the value, because the field is not supported
  or for some other reason, an exception is thrown.
  <p>
  The value for the {@link IsoFields#WEEK_BASED_YEAR WEEK_BASED_YEAR} and
  {@link IsoFields#WEEK_OF_WEEK_BASED_YEAR WEEK_OF_WEEK_BASED_YEAR} fields is returned.
  All {@link ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}.
  
  @param field  the field to get, not null
  @return the value for the field
  @throws DateTimeException if a value for the field cannot be obtained
  @throws UnsupportedTemporalTypeException if the field is not supported
  @throws ArithmeticException if numeric overflow occurs