java -client4.1 "EventFiringWebDriverFactory.getEventFiringWebDriver"capabilities turn to null #450

Description

use java-client 4.1 found 👍

capabilities.setCapability(MobileCapabilityType.BROWSER_NAME, browser_Name);
capabilities.setCapability(MobileCapabilityType.PLATFORM_NAME, platform_Name);
capabilities.setCapability(MobileCapabilityType.DEVICE_NAME,device_Name);
capabilities.setCapability(MobileCapabilityType.PLATFORM_VERSION, platform_Version);

  driver = new AndroidDriver(new URL(hubURL),capabilities);
  driver2= EventFiringWebDriverFactory.getEventFiringWebDriver(driver, new AlertListener(), new ElementListener());

the driver2 is null!!!!!

when i debug found when the code run into "EventFiringWebDriverFactory.getEventFiringWebDriver(driver, new AlertListener(), new ElementListener());"

the capabilities turn to null;

Environment

jdk 1,7
java -client 4.1
selenium 2.53