* and {@code distance(end, start) == -3}. As well, {@code distance(a, a)} is always zero.
   *
   * <p>Note that this function is necessarily well-defined for any discrete type.
   *
   * @return the distance as described above, or {@link Long#MIN_VALUE} or {@link Long#MAX_VALUE} if
   *     the distance is too small or too large, respectively.
   */
  public abstract long distance(C start, C end);

  /**

   * and {@code distance(end, start) == -3}. As well, {@code distance(a, a)} is always zero.
   *
   * <p>Note that this function is necessarily well-defined for any discrete type.
   *
   * @return the distance as described above, or {@link Long#MIN_VALUE} or {@link Long#MAX_VALUE} if
   *     the distance is too small or too large, respectively.
   */
  public abstract long distance(C start, C end);

  /**