*
   * @param string a string reference to check
   * @return {@code true} if the string is null or is the empty string
   */
  public static boolean isNullOrEmpty(@CheckForNull String string) {
    return Platform.stringIsNullOrEmpty(string);
  }

  /**
   * Returns a string, of length at least {@code minLength}, consisting of {@code string} prepended

    private static final String SECRET_PATTERN = "^(smb.*:).*(@.*)$";
    private static final String SECRET_MASK_REPLACE = "$1******$2";

    /**
     * 
     */
    private Strings () {}


    /**
     * 
     * @param str
     * @param encoding
     * @return encoded
     */
    public static byte[] getBytes ( String str, Charset encoding ) {
        if ( str == null ) {

      }
    }

    String stringA = new String(charsA);
    String stringB = new String(charsB);
    assertThat(stringA).isNotEqualTo(stringB);
    assertThat(HASH_FN.hashUnencodedChars(stringA))
        .isNotEqualTo(HASH_FN.hashUnencodedChars(stringB));
    assertThat(fingerprint(stringA.getBytes(UTF_8)))
        .isNotEqualTo(fingerprint(stringB.getBytes(UTF_8)));

    String[] array = new String[elements.length];
    int i = 0;
    for (Object e : elements) {
      array[i++] = (String) e;
    }
    return create(array);
  }

  protected abstract Queue<String> create(String[] elements);

  @Override
  public String[] createArray(int length) {
    return new String[length];
  }

  /** Returns the original element list, unchanged. */
  @Override

    String[] array = new String[elements.length];
    int i = 0;
    for (Object e : elements) {
      array[i++] = (String) e;
    }
    return create(array);
  }

  /**
   * Creates a new collection containing the given elements; implement this method instead of {@link
   * #create(Object...)}.
   */
  protected abstract List<String> create(String[] elements);

  @Override

   * </ul>
   *
   * @param string the literal string to be escaped
   * @return the escaped form of {@code string}
   * @throws NullPointerException if {@code string} is null
   * @throws IllegalArgumentException if {@code string} contains badly formed UTF-16 or cannot be
   *     escaped for any other reason
   */
  public abstract String escape(String string);

  static final Integer NODE_NOT_IN_GRAPH = 1000;

  // TODO(user): Consider separating Strings that we've defined here to capture
  // identifiable substrings of expected error messages, from Strings that we've defined
  // here to provide error messages.
  // TODO(user): Some Strings used in the subclasses can be added as static Strings
  // here too.
  static final String ERROR_MODIFIABLE_SET = "Set returned is unexpectedly modifiable";

            return StringUtil.EMPTY_STRINGS;
        }
        return split(value, ",").get(stream -> stream.filter(StringUtil::isNotBlank).map(String::trim).toArray(n -> new String[n]));
    }

    public static class OpenIdUser implements FessUser {

        private static final long serialVersionUID = 1L;

        protected final String name;

        protected String[] groups;

        protected String[] roles;

    @Override
    protected Set<String> create(String[] elements) {
      return ImmutableSet.copyOf(elements);
    }
  }

  public static class ImmutableSetUnsizedBuilderGenerator extends TestStringSetGenerator {
    @Override
    protected Set<String> create(String[] elements) {
      ImmutableSet.Builder<String> builder = ImmutableSet.builder();
      for (String e : elements) {
        builder.add(e);
      }

        new EntryTransformer<String, String, String>() {
          @Override
          public String transformEntry(String key, String value) {
            return key + value;
          }
        };
    SortedMap<String, String> transformed = transformEntries(map, concat);

    /*
     * We'd like to sanity check that we didn't get a NavigableMap out, but we