public <T> List<T> getCapabilities( CapabilityName<T> name ) {
		if( graph == null ) {
			return Collections.emptyList();
		}
		List<T> result = new ArrayList<>();
		for( GraphItem item : graph.getItems() ) {
			T capability = item.getCapability( name );
			if( capability != null ) {
				result.add( capability );
			}
		}
		return result;
	}