}
    this.plusForSpace = plusForSpace;
    this.safeOctets = createSafeOctets(safeChars);
  }

  /**
   * Creates a boolean array with entries corresponding to the character values specified in
   * safeChars set to true. The array is as small as is required to hold the given character
   * information.
   */
  private static boolean[] createSafeOctets(String safeChars) {
    int maxChar = -1;