question: public String toString ( ) { final StringBuilder sb = new StringBuilder ( ) ; sb . append ( "BlockingIterator" ) ; sb . append ( "{ open=" + open ) ; sb . append ( ", futureIsDone=" + futureIsDone ) ; sb . append ( ", bufferIsOpen=" + BlockingBuffer . this . open ) ; sb . append ( ", nextE=" + ( nextE != null ) ) ; sb . append ( "}" ) ; return sb . toString ( ) ; }
target:  Safe non-blocking representation of the iterator state.