code: public void addConnectionFactory(ConnectionFactory<?> connectionFactory) {
  		if (connectionFactories.containsKey(connectionFactory.getProviderId())) {
  			throw new IllegalArgumentException("A ConnectionFactory for provider '" + connectionFactory.getProviderId() + "' has already been registered");
  		}
  		Class<?> apiType = GenericTypeResolver.resolveTypeArgument(connectionFactory.getClass(), ConnectionFactory.class);
  		if (apiTypeIndex.containsKey(apiType)) {
  			throw new IllegalArgumentException("A ConnectionFactory for API [" + apiType.getName() + "] has already been registered");
  		}
  		connectionFactories.put(connectionFactory.getProviderId(), connectionFactory);
  		apiTypeIndex.put(apiType, connectionFactory.getProviderId());
  	}
docs: Add a {@link ConnectionFactory} to this registry.
  @param connectionFactory the connection factory