@Override
    public boolean hasQueuedWriterThreads() {
        return writerLock.hasQueuedThreads();
    }
Relinquishes exclusive write access to the Guacamole instruction
stream. This function should be called whenever a thread finishes using
a GuacamoleTunnel's GuacamoleWriter.
guacamole-common/src/main/java/org/apache/guacamole/net/AbstractGuacamoleTunnel.java