/** Restricted constructor */
 GJEraDateTimeField(BasicChronology chronology) {
   super(DateTimeFieldType.era());
   iChronology = chronology;
 }
 /**
  * Get the era field for this chronology.
  *
  * @return DateTimeField or UnsupportedDateTimeField if unsupported
  */
 public DateTimeField era() {
   return UnsupportedDateTimeField.getInstance(DateTimeFieldType.era(), eras());
 }