code: public Uid setUid(String uid) {
  		Uid property = (uid == null) ? null : new Uid(uid);
  		setUid(property);
  		return property;
  	}
docs: Sets the calendar's unique identifier.
  @param uid the unique identifier or null to remove
  @return the property object that was created
  @see <a
  href="http://tools.ietf.org/html/draft-ietf-calext-extensions-01#page-6">draft-ietf-calext-extensions-01
  p.6</a>