code: public DateEnd setDateEnd(Date dateEnd, boolean hasTime) {
  		DateEnd prop = (dateEnd == null) ? null : new DateEnd(dateEnd, hasTime);
  		setDateEnd(prop);
  		return prop;
  	}
docs: Sets the date that the event ends. This must NOT be set if a
  {@link DurationProperty} is defined.
  @param dateEnd the end date or null to remove
  @param hasTime true if the date has a time component, false if it is
  strictly a date (if false, the given Date object should be created by a
  {@link java.util.Calendar Calendar} object that uses the JVM's default
  timezone)
  @return the property that was created
  @see <a href="http://tools.ietf.org/html/rfc5545#page-95">RFC 5545
  p.95-6</a>
  @see <a href="http://tools.ietf.org/html/rfc2445#page-91">RFC 2445
  p.91-2</a>
  @see <a href="http://www.imc.org/pdi/vcal-10.doc">vCal 1.0 p.31</a>