new Function<@Nullable String, @Nullable Character>() {
        @Override
        public @Nullable Character apply(@Nullable String input) {
          return input == null ? null : input.charAt(0);
        }
      };

  @Override
  protected Table<String, Integer, Character> create(@Nullable Object... data) {
    Table<String, Integer, String> table = HashBasedTable.create();

    for (int i = 0, len = charSequence.length(); i < len; i++) {
      putChar(charSequence.charAt(i));
    }
    return this;
  }

  @Override
  @CanIgnoreReturnValue
  public Hasher putString(CharSequence charSequence, Charset charset) {
    return putBytes(charSequence.toString().getBytes(charset));
  }

  @Override
  @CanIgnoreReturnValue
  public Hasher putBytes(byte[] bytes) {

        while ( p < len && ( ch = pathInfo.charAt(p) ) != '/' ) {
            out[ i++ ] = ch;
            p++;
        }
        while ( p < len && pathInfo.charAt(p) == '/' ) {
            p++;
        }
        if ( p < len ) { /* then there must be a share */
            out[ i++ ] = '/';
            do { /* collect the share name */
                out[ i++ ] = ( ch = pathInfo.charAt(p++) );
            }

    }
    private String parseServerAndShare( String pathInfo ) {
        char[] out = new char[256];
        char ch;
        int len, p, i;

        if( pathInfo == null ) {
            return null;
        }
        len = pathInfo.length();

        p = i = 0;
        while( p < len && pathInfo.charAt( p ) == '/' ) {
            p++;
        }
        if( p == len ) {

                if (_klen == key.length()) {
                    match = _key.equals(key);
                } else if (_klen < key.length()) {
                    match = _key.regionMatches(0, key, 0, _klen) && key.charAt(_klen) == '\\';
                }

                if (match)
                    dr = (DfsReferral)referrals.map.get(_key);
            }
        }

        return dr;
    }

    Set<Character> positive = Sets.newHashSetWithExpectedSize(chars.length);
    for (char c : chars) {
      positive.add(c);
    }
    for (int c = 0; c <= Character.MAX_VALUE; c++) {
      assertFalse(positive.contains(Character.valueOf((char) c)) ^ m.matches((char) c));
    }
  }

  static char[] randomChars(Random rand, int size) {
    Set<Character> chars = new HashSet<>(size);

    Set<Character> positive = Sets.newHashSetWithExpectedSize(chars.length);
    for (char c : chars) {
      positive.add(c);
    }
    for (int c = 0; c <= Character.MAX_VALUE; c++) {
      assertFalse(positive.contains(Character.valueOf((char) c)) ^ m.matches((char) c));
    }
  }

  static char[] randomChars(Random rand, int size) {
    Set<Character> chars = new HashSet<>(size);

    static String unescape( String str ) throws NumberFormatException, UnsupportedEncodingException {
        char ch;
        int i, j, state, len;
        char[] out;
        byte[] b = new byte[1];

        if( str == null ) {
            return null;
        }

        len = str.length();
        out = new char[len];
        state = 0;
        for( i = j = 0; i < len; i++ ) {
            switch( state ) {

   */
  private static char[] growBuffer(char[] dest, int index, int size) {
    if (size < 0) { // overflow - should be OutOfMemoryError but GWT/j2cl don't support it
      throw new AssertionError("Cannot increase internal buffer any further");
    }
    char[] copy = new char[size];
    if (index > 0) {
      System.arraycopy(dest, 0, copy, 0, index);
    }

    static String unescape ( String str ) throws NumberFormatException, UnsupportedEncodingException {
        char ch;
        int i, j, state, len;
        char[] out;
        byte[] b = new byte[1];

        if ( str == null ) {
            return null;
        }

        len = str.length();
        out = new char[len];
        state = 0;
        for ( i = j = 0; i < len; i++ ) {
            switch ( state ) {