private static void fixChannelMock(AbstractInterruptibleChannel mockFileChannel) throws Exception {
    // Note : This is a workaround for NullPointerException.
    // This will break when jdk decides to change implementation.
    Field closeLockField = AbstractInterruptibleChannel.class.getDeclaredField("closeLock");
    closeLockField.setAccessible(true);
    closeLockField.set(mockFileChannel, new Object());
}