code: public void addContextDataFactory(ContextDataFactory contextDataFactory) {
  		if (contextDataFactory == null) {
  			throw new IllegalArgumentException("Parameter contextDataFactory must not be null.");
  		}
  		this.contextDataFactories.add(contextDataFactory);
  
  		if (postInitialisation) {
  			for (Context context : getSession().getContexts()) {
  				contextDataFactory.loadContextData(getSession(), context);
  			}
  		}
  	}
docs: Adds the given context data factory to the model.
  
  @param contextDataFactory the context data factory that will be added.
  @throws IllegalArgumentException if the given parameter is {@code null}.
  @see #removeContextDataFactory(ContextDataFactory)