_[Original issue](https://code.google.com/p/guava-libraries/issues/detail?id=1813) created by **j...@nwsnet.de** on 2014-07-23 at 03:21 PM_

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I didn't find information on the immutability of `Range`&nbsp;instances in the JavaDocs [1]; only the wiki page [2] explicitly states it.

I suggest documenting the immutability directly in the JavaDocs, and thus in the implementation itself.

[1] https://google.github.io/guava/apidocs/com/google/common/collect/Range.html
[2] https://code.google.com/p/guava-libraries/wiki/RangesExplained

(Slightly unrelated: The comments disappeared from the wiki, especially helpful ones which I remembered to be on the page on ranges are gone. I'd like to state that I don't welcome that change.)

* than {@code upper}.
   *
   * @throws IllegalArgumentException if {@code lower} is greater than <i>or equal to</i> {@code
   *     upper}
   * @throws ClassCastException if {@code lower} and {@code upper} are not mutually comparable
   * @since 14.0
   */
  public static <C extends Comparable<?>> Range<C> open(C lower, C upper) {
    return create(Cut.aboveValue(lower), Cut.belowValue(upper));
  }
  /**
   * Returns a range that contains all values greater than or equal to {@code lower} and less than
   * or equal to {@code upper}.
   *
   * @throws IllegalArgumentException if {@code lower} is greater than {@code upper}
   * @throws ClassCastException if {@code lower} and {@code upper} are not mutually comparable
   * @since 14.0
   */
  public static <C extends Comparable<?>> Range<C> closed(C lower, C upper) {
    return create(Cut.belowValue(lower), Cut.aboveValue(upper));
  }
  /**
   * Returns a range that contains all values greater than or equal to {@code lower} and strictly
   * less than {@code upper}.
   *
   * @throws IllegalArgumentException if {@code lower} is greater than {@code upper}
   * @throws ClassCastException if {@code lower} and {@code upper} are not mutually comparable
   * @since 14.0
   */
  public static <C extends Comparable<?>> Range<C> closedOpen(C lower, C upper) {