private static <T> T forwardFd(final Procedure<T, FileNotFoundException> procedure) throws FileNotFoundException {
		final long caller = Binder.clearCallingIdentity();
		try { return procedure.execute(); }
		finally { Binder.restoreCallingIdentity(caller); }
	}
Reset calling identity to eliminate possible SecurityException thrown from the target provider.
fileprovider/src/main/java/com/oasisfeng/island/fileprovider/ShuttleProvider.java