/guava/android/guava/src/com/google/common/util/concurrent/AbstractFuture.java
if ( old != update) {   future.listeners = update; }
[Delete]
return false; } } @Override boolean casListeners(AbstractFuture<?> future, @CheckForNull Listener expect, Listener update) { synchronized (future) { <extra_id_0> future.listeners = update; return true; } return false; } }