code: public List<Display> getDisplays() {
  		return new EnumParameterList<Display>(DISPLAY) {
  			@Override
  			protected Display _asObject(String value) {
  				return Display.get(value);
  			}
  		};
  	}
docs: <p>
  Gets the DISPLAY parameter values.
  </p>
  <p>
  This parameter is used by the {@link Image} property. It defines the ways
  in which the client application should display the image (for example, as
  a thumbnail-sized image).
  </p>
  <p>
  Changes to the returned list will update the {@link ICalParameters}
  object, and vice versa.
  </p>
  @return the display suggestions or empty list if none are defined
  @see <a href=
  "https://tools.ietf.org/html/draft-ietf-calext-extensions-01#page-13" >
  draft-ietf-calext-extensions p.13</a>