presto-main/src/main/java/io/prestosql/execution/buffer/ClientBuffer.java/ClientBuffer/isDestroyed
class ClientBuffer:    public boolean isDestroyed()
    {
        //
        // NOTE: this code must be lock free so state machine updates do not hang
        //
        @SuppressWarnings("FieldAccessNotGuarded")
        boolean destroyed = this.destroyed.get();
        return destroyed;
    }