}

    public static String key(String groupId, String artifactId, String version) {
        notBlank(groupId, "groupId can neither be null, empty nor blank");
        notBlank(artifactId, "artifactId can neither be null, empty nor blank");
        notBlank(version, "version can neither be null, empty nor blank");

        return groupId + ":" + artifactId + ":" + version;
    }

   * <p>The returned set's {@link Object#toString} method returns a shorthand form of the set's
   * contents, such as {@code "[1..100]}"}.
   *
   * @throws IllegalArgumentException if neither this range nor the domain has a lower bound, or if
   *     neither has an upper bound
   */
  public ImmutableSortedSet<C> asSet(DiscreteDomain<C> domain) {
    checkNotNull(domain);
    if (isEmpty()) {
      return ImmutableSortedSet.of();

   * array nor its contents can be null, but it is not useful to force the use of {@code
   * requireNonNull} or the like just to assert that.
   *
   * <p>{@code EqualsTester} will always check that every object it is given returns false from
   * {@code equals(null)}, so it is neither useful nor allowed to include a null value in any
   * equality group.
   */

   * Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the
distribution.
   * Neither the name of Google Inc. nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.

   * Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the
distribution.
   * Neither the name of Google LLC nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.

   * Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the
distribution.
   * Neither the name of Google Inc. nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.

   * Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the
distribution.
   * Neither the name of Google Inc. nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.

   * Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the
distribution.
   * Neither the name of Google Inc. nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.

    Redistributions in binary form must reproduce the above copyright
    notice, this list of conditions and the following disclaimer in
    the documentation and/or other materials provided with the
    distribution.

    Neither the name of the Open Knowledge Foundation Ltd. nor the
    names of its contributors may be used to endorse or promote
    products derived from this software without specific prior written
    permission.

   * Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the
distribution.
   * Neither the name of Google Inc. nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.