Optional. Indicates that the pass is void—for example, a one time use coupon that has been redeemed. The default value is false. Available in iOS 7.0.
But if "false" value is set from Java code (as it's done now), than this key is always included (with "false" by default). So it becomes mandatory instead of optional, what is incorrect and useless.
According to the Passbook documentation: https://developer.apple.com/library/ios/documentation/UserExperience/Reference/PassKit_Bundle/Chapters/TopLevel.html#//apple_ref/doc/uid/TP40012026-CH2-SW2
But if "false" value is set from Java code (as it's done now), than this key is always included (with "false" by default). So it becomes mandatory instead of optional, what is incorrect and useless.