* Enable or disable popular word tracking and display.
     * When enabled, frequently searched terms are tracked and displayed.
     */
    @Size(max = 10)
    public String popularWord;

    /**
     * Character encoding to use for CSV file exports.
     * This setting affects the encoding of downloaded CSV files.
     */
    @Required
    @Size(max = 20)
    public String csvFileEncoding;

    /**

        checkVersionsEqual("1.0", "1.0.0");
        checkVersionsEqual("1", "1-0");
        checkVersionsEqual("1", "1.0-0");
        checkVersionsEqual("1.0", "1.0-0");
        // no separator between number and character
        checkVersionsEqual("1a", "1-a");
        checkVersionsEqual("1a", "1.0-a");
        checkVersionsEqual("1a", "1.0.0-a");
        checkVersionsEqual("1.0a", "1-a");
        checkVersionsEqual("1.0.0a", "1-a");

## Edit PR Titles

* Edit the PR title to start with an emoji from [gitmoji](https://gitmoji.dev/).
    * Use the emoji character, not the GitHub code. So, use `🐛` instead of `:bug:`. This is so that it shows up correctly outside of GitHub, for example in the release notes.
    * For translations use the `🌐` emoji ("globe with meridians").

	// this is kept in present form to be compatible with S3 owner ID
	// requirements -
	//
	// ```
	//    The canonical user ID is the Amazon S3–only concept.
	//    It is 64-character obfuscated version of the account ID.
	// ```
	// http://docs.aws.amazon.com/AmazonS3/latest/dev/example-walkthroughs-managing-access-example4.html

      negligent acts) or agreed to in writing, shall any Contributor be
      liable to You for damages, including any direct, indirect, special,
      incidental, or consequential damages of any character arising as a
      result of this License or out of the use or inability to use the
      Work (including but not limited to damages for loss of goodwill,
      work stoppage, computer failure or malfunction, or any and all

 * Hc5FormScheme formScheme = new Hc5FormScheme(params);
 * formScheme.authenticate(credentials, executor);
 * }
 * </pre>
 *
 * <p>Parameters:
 * <ul>
 * <li>ENCODING - The character encoding to use for request parameters.</li>
 * <li>TOKEN_URL - The URL to request the token from.</li>
 * <li>TOKEN_PATTERN - The regex pattern to extract the token from the response.</li>

  private enum CharAtFunction implements Function<String, Character> {
    AT0(0),
    AT1(1),
    AT2(2),
    AT3(3),
    AT4(4),
    AT5(5),
    ;

    final int index;

    CharAtFunction(int index) {
      this.index = index;
    }

    @Override
    public Character apply(String string) {
      return string.charAt(index);
    }
  }

  private enum CharAtFunction implements Function<String, Character> {
    AT0(0),
    AT1(1),
    AT2(2),
    AT3(3),
    AT4(4),
    AT5(5),
    ;

    final int index;

    CharAtFunction(int index) {
      this.index = index;
    }

    @Override
    public Character apply(String string) {
      return string.charAt(index);
    }
  }

          "Only a colon may follow a close bracket: %s",
          hostPortString);
      for (int i = closeBracketIndex + 2; i < hostPortString.length(); ++i) {
        checkArgument(
            Character.isDigit(hostPortString.charAt(i)),
            "Port must be numeric: %s",
            hostPortString);
      }
      return new String[] {host, hostPortString.substring(closeBracketIndex + 2)};
    }
  }

 * FormScheme formScheme = new FormScheme(params);
 * formScheme.authenticate(credentials, executor);
 * }
 * </pre>
 *
 * <p>Parameters:
 * <ul>
 * <li>ENCODING - The character encoding to use for request parameters.</li>
 * <li>TOKEN_URL - The URL to request the token from.</li>
 * <li>TOKEN_PATTERN - The regex pattern to extract the token from the response.</li>