public ConsoleLoggerBuilder warn(Consumer<String> messageConsumer) {
    messageConsumers.put(Level.WARN, messageConsumer);
    return this;
  }
Sets the {@link Consumer} to log a {@link Level#WARN} message.

@param messageConsumer the message {@link Consumer}
@return this
jib-plugins-common/src/main/java/com/google/cloud/tools/jib/plugins/common/logging/ConsoleLoggerBuilder.java