code: public static <K extends Message> MessageListener<K> from(Integer channelIdentifier, Consumer<K> consumer) {
          return new ConsumerMessageListener<>(channelIdentifier, consumer);
      }
docs: Lambda support. Takes in a consumer and wraps a MessageListener object around it, since the message listener is
  not a functional interface.
  @param channelIdentifier Integer identifier of the channel/pin to listen to.
  @param consumer Lambda logic to be run against the received message.
  @param <K> Message type to listen for.
  @return New MessageListener for the given type and logic.