*
   * @since 20.0 (varargs overload since 2.0)
   */
  public static void checkArgument(
      boolean expression, String errorMessageTemplate, char p1, char p2) {
    if (!expression) {
      throw new IllegalArgumentException(lenientFormat(errorMessageTemplate, p1, p2));
    }
  }

  /**
   * Ensures the truth of an expression involving one or more parameters to the calling method.
   *