bug in phonemovement

The app shutdown because an invalid number was added.
java.lang.NumberFormatException: For input string: ""
        at java.lang.NumberFormatException.forInputString(NumberFormatException.java:48)
        at java.lang.Integer.parseInt(Integer.java:470)
        at java.lang.Integer.<init>(Integer.java:660)
        at com.datatorrent.demos.mobile.PhoneMovementGenerator.registerPhone(PhoneMovementGenerator.java:205)
        at com.datatorrent.demos.mobile.PhoneMovementGenerator.processQuery(PhoneMovementGenerator.java:151)
        at com.datatorrent.demos.mobile.PhoneMovementGenerator.access$600(PhoneMovementGenerator.java:42)
        at com.datatorrent.demos.mobile.PhoneMovementGenerator$2.process(PhoneMovementGenerator.java:108)
        at com.datatorrent.demos.mobile.PhoneMovementGenerator$2.process(PhoneMovementGenerator.java:104)
        at com.datatorrent.api.DefaultInputPort.put(DefaultInputPort.java:67)
        at com.datatorrent.stram.stream.BufferServerSubscriber$BufferReservoir.sweep(BufferServerSubscriber.java:217)
        at com.datatorrent.stram.engine.GenericNode.run(GenericNode.java:202)
        at com.datatorrent.stram.StramChild$2.run(StramChild.java:1186)