private final Iterator<Map.Entry<E, AtomicInteger>> mapEntries =
              countMap.entrySet().iterator();

          @Override
          protected @Nullable Entry<E> computeNext() {
            while (true) {
              if (!mapEntries.hasNext()) {
                return endOfData();
              }
              Map.Entry<E, AtomicInteger> mapEntry = mapEntries.next();

          private final Iterator<Map.Entry<E, AtomicInteger>> mapEntries =
              countMap.entrySet().iterator();

          @Override
          protected @Nullable Entry<E> computeNext() {
            while (true) {
              if (!mapEntries.hasNext()) {
                return endOfData();
              }
              Map.Entry<E, AtomicInteger> mapEntry = mapEntries.next();

      this.omitEmptyStrings = splitter.omitEmptyStrings;
      this.limit = splitter.limit;
      this.toSplit = toSplit;
    }

    @Override
    protected @Nullable String computeNext() {
      /*
       * The returned string will be from the end of the last match to the beginning of the next
       * one. nextStart is the start position of the returned substring, while offset is the place

      return new AbstractIterator<String>() {
        final Iterator<String> lines = LINE_SPLITTER.split(seq).iterator();

        @Override
        protected @Nullable String computeNext() {
          if (lines.hasNext()) {
            String next = lines.next();
            // skip last line if it's empty
            if (lines.hasNext() || !next.isEmpty()) {
              return next;

      this.omitEmptyStrings = splitter.omitEmptyStrings;
      this.limit = splitter.limit;
      this.toSplit = toSplit;
    }

    @Override
    protected @Nullable String computeNext() {
      /*
       * The returned string will be from the end of the last match to the beginning of the next
       * one. nextStart is the start position of the returned substring, while offset is the place

      Iterator<T> unfiltered, Predicate<? super T> retainIfTrue) {
    checkNotNull(unfiltered);
    checkNotNull(retainIfTrue);
    return new AbstractIterator<T>() {
      @Override
      protected @Nullable T computeNext() {
        while (unfiltered.hasNext()) {
          T element = unfiltered.next();
          if (retainIfTrue.apply(element)) {
            return element;
          }
        }
        return endOfData();

      Iterator<T> unfiltered, Predicate<? super T> retainIfTrue) {
    checkNotNull(unfiltered);
    checkNotNull(retainIfTrue);
    return new AbstractIterator<T>() {
      @Override
      protected @Nullable T computeNext() {
        while (unfiltered.hasNext()) {
          T element = unfiltered.next();
          if (retainIfTrue.apply(element)) {
            return element;
          }
        }
        return endOfData();

    @Override
    public Iterator<ReferenceEntry<K, V>> iterator() {
      return new AbstractSequentialIterator<ReferenceEntry<K, V>>(peek()) {
        @Override
        protected @Nullable ReferenceEntry<K, V> computeNext(ReferenceEntry<K, V> previous) {
          ReferenceEntry<K, V> next = previous.getNextInWriteQueue();
          return (next == head) ? null : next;
        }
      };
    }
  }

  /**

    @Override
    public Iterator<ReferenceEntry<K, V>> iterator() {
      return new AbstractSequentialIterator<ReferenceEntry<K, V>>(peek()) {
        @Override
        protected @Nullable ReferenceEntry<K, V> computeNext(ReferenceEntry<K, V> previous) {
          ReferenceEntry<K, V> next = previous.getNextInWriteQueue();
          return (next == head) ? null : next;
        }
      };
    }
  }

  /**