toIndex = mappingItemList.size();
        }

        return new PagingList<>(mappingItemList.subList(offset, toIndex), offset, size, mappingItemList.size());
    }

    /**
     * Inserts a new character mapping item into the dictionary file.
     *
     * @param item the character mapping item to insert
     */
    @Override
    public synchronized void insert(final CharMappingItem item) {