code: public Collection<VTimezone> getComponents() {
  		List<VTimezone> components = new ArrayList<VTimezone>(assignments.size());
  		for (TimezoneAssignment assignment : assignments) {
  			VTimezone component = assignment.getComponent();
  			if (component != null) {
  				components.add(component);
  			}
  		}
  		return Collections.unmodifiableList(components);
  	}
docs: Gets all of the iCalendar {@link VTimezone} components that have been
  registered with this object.
  @return the components (this collection is immutable)