@Deprecated
  public static CharMatcher javaLetter() {
    return JavaLetter.INSTANCE;
  }

  /**
   * Determines whether a character is a BMP letter or digit according to {@linkplain
   * Character#isLetterOrDigit(char) Java's definition}.
   *
   * @deprecated Most letters and digits are supplementary characters; see the class documentation.
   * @since 19.0 (since 1.0 as constant {@code JAVA_LETTER_OR_DIGIT}).
   */