question: public final void decRef ( ) throws IOException { ensureOpen ( ) ; final int rc = refCount . decrementAndGet ( ) ; if ( rc == 0 ) { boolean success = false ; try { doClose ( ) ; closed = true ; success = true ; } finally { if ( ! success ) { refCount . incrementAndGet ( ) ; } } } else if ( rc < 0 ) { throw new IllegalStateException ( "too many decRef calls: refCount is " + rc + " after decrement" ) ; } }
target:  Expert: decreases the refCount of this TaxonomyReader instance. If the refCount drops to 0 this taxonomy reader is closed.