Cross Reference: /developers/build/prebuilts/gradle/CustomNotifications/CustomNotificationsSample/src/main/res/drawable-xhdpi

`Name`	`Date`	`Size`
Up to higher level directory
`ic_launcher.png`	03-Jun-2014	`7K`
`ic_stat_custom.png`	03-Jun-2014	`2.3K`
`robot.png`	03-Jun-2014	`5.4K`
`robot_expanded.png`	03-Jun-2014	`18K`