code: public LastModified setLastModified(Date lastModified) {
  		LastModified property = (lastModified == null) ? null : new LastModified(lastModified);
  		setLastModified(property);
  		return property;
  	}
docs: Sets the date and time that the information in this calendar object was
  last revised.
  @param lastModified the date and time 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-7">draft-ietf-calext-extensions-01
  p.7</a>