public void put(int key, E value) {
            // Insert key as active
            int currentPos = locate( key );
            if( isActive( currentPos ) )
                return;

            array[ currentPos ] = new HashEntry<E> ( key, value, true );

            // Rehash
            if( ++currentSize > array.length / 2 )
                rehash( );
        }
Insert into the hash table. If the item is
already present, do nothing.
@param key the item to insert.
subs/gif-revert/src/main/java/com/engineer/gif/revert/lib/AnimatedGIFWriter.java