return (reader instanceof BufferedReader)
        ? (BufferedReader) reader
        : new BufferedReader(reader);
  }

  /**
   * Opens a new {@link Stream} for reading text one line at a time from this source. This method
   * returns a new, independent stream each time it is called.
   *
   * <p>The returned stream is lazy and only reads from the source in the terminal operation. If an

 *
 * BufferedReader reader = ...;
 * for (String line : iterable(reader)) {
 *     ...
 * }
 * </pre>
 *
 * @author koichik
 */
public class LineIterator implements Iterator<String> {

    /** {@link #line}が空であることを示す{@literal String}オブジェクト */
    protected static final String EMPTY = new String();

    /** {@link BufferedReader} */
    protected final BufferedReader reader;

    /** 読み込み済みの文字列 */

    }

    protected static void updateDefaultBadwords() {
        if (defaultWords != null) {
            return;
        }

        final List<String> list = new ArrayList<>();
        try (BufferedReader br = new BufferedReader(new InputStreamReader(
                Thread.currentThread().getContextClassLoader().getResourceAsStream("suggest_settings/default-badwords.txt")))) {

            String line;

        final Pattern parsePattern = Pattern.compile("(.*)\\s*=>\\s*(.*)\\s*$");
        final List<CharMappingItem> itemList = new ArrayList<>();
        try (BufferedReader reader = new BufferedReader(new InputStreamReader(in, Constants.UTF_8))) {
            long id = 0;
            String line = null;
            while ((line = reader.readLine()) != null) {
                // Remove comments

        if (!enabled) {
            return null;
        }

        try {
            @SuppressWarnings("resource")
            final BufferedReader reader = new BufferedReader(new InputStreamReader(new BOMInputStream(stream), charsetName));

            String line;
            final RobotsTxt robotsTxt = new RobotsTxt();

    }

    private String getDefaultMappings() throws IOException {
        final StringBuilder mappingSource = new StringBuilder();
        try (BufferedReader br = new BufferedReader(new InputStreamReader(
                this.getClass().getClassLoader().getResourceAsStream("suggest_indices/suggest/mappings-default.json")))) {

            String line;

        verifyTokenKeep(() -> asListHtml(this::saveToken));

        String header = null;
        final StringBuilder buf = new StringBuilder(1000);
        try (final BufferedReader reader = new BufferedReader(new InputStreamReader(form.requestFile.getInputStream(), Constants.UTF_8))) {
            header = ReaderUtil.readLine(reader);
            if (header == null) {

        }
    }

    /**
     * {@link BufferedReader}から一行読み込んで返します。
     *
     * @param reader
     *            {@link BufferedReader}。{@literal null}であってはいけません
     * @return 一行の文字列。終端に達した場合は{@literal null}
     * @see BufferedReader#readLine()
     */
    public static String readLine(final BufferedReader reader) {
        assertArgumentNotNull("reader", reader);

        try {

        final String dictionaryPath = System.getProperty("fess.dictionary.path", StringUtil.EMPTY);
        final StringBuilder sb = new StringBuilder();
        try (BufferedReader br = new BufferedReader(
                new InputStreamReader(this.getClass().getClassLoader().getResourceAsStream("suggest_indices/suggest_settings.json")));) {

            String line;

        try (BufferedReader br = new BufferedReader(readerSupplier.open(), BUFFER_SIZE)) {
            br.mark(BUFFER_SIZE);
            XMLStreamReader xsr = XMLInputFactory.newFactory().createXMLStreamReader(br);
            xsr.nextTag();
            String nsUri = xsr.getNamespaceURI();
            try (BufferedReader br2 = reset(readerSupplier, br)) {