newComparable("0-x");
        newComparable("0.rc");
        newComparable("0-1");

        ComparableVersion version = new ComparableVersion("0.x");
        assertEquals("x", version.getCanonical());
        ComparableVersion version2 = new ComparableVersion("0.2");
        assertEquals("0.2", version2.getCanonical());
    }

    /**
     * Test <a href="https://issues.apache.org/jira/browse/MNG-5568">MNG-5568</a> edge case

                                        if (versions == null) {
                                            versions = source.retrieveAvailableVersions(metadataRequest);
                                            artifact.setAvailableVersions(versions);
                                        }

                                        Collections.sort(versions);

     *         of this version range and the specified version range if both version ranges have
     *         restrictions. Otherwise, the restrictions on the returned range will be empty.
     *         </p>
     *         <p>
     *         The recommended version of the returned version range will be the recommended version of
     *         this version range, provided that ranges falls within the intersected restrictions. If

            version = versions.releaseVersion;
            repo = versions.releaseRepository;
        } else if (versions.latestVersion != null && !versions.latestVersion.isEmpty()) {
            version = versions.latestVersion;
            repo = versions.latestRepository;
        }
        if (version != null && !isCompatible(request, version)) {

                .map(MavenProject::getVersion)
                .collect(Collectors.collectingAndThen(Collectors.toList(), Collections::unmodifiableList));
        if (!versions.isEmpty()) {
            return versions;
        }
        return getAllProjects()
                .getOrDefault(artifact.getGroupId(), Collections.emptyMap())
                .getOrDefault(artifact.getArtifactId(), Collections.emptyMap())
                .values()

   * exception's creation.
   *
   * @since 19.0
   * @deprecated This method is equivalent to {@link Throwable#getStackTrace()} on JDK versions past
   *     JDK 8 and on all Android versions. Use {@link Throwable#getStackTrace()} directly, or where
   *     possible use the {@code java.lang.StackWalker.walk} method introduced in JDK 9.
   */
  @Deprecated
  @J2ktIncompatible

   * exception's creation.
   *
   * @since 19.0
   * @deprecated This method is equivalent to {@link Throwable#getStackTrace()} on JDK versions past
   *     JDK 8 and on all Android versions. Use {@link Throwable#getStackTrace()} directly, or where
   *     possible use the {@code java.lang.StackWalker.walk} method introduced in JDK 9.
   */
  @Deprecated
  @J2ktIncompatible

     * construct graph from a "dirty" tree
     *
     * @param tree "dirty" tree root
     * @param versionedVertices true if graph nodes should be versioned (different versions -> different nodes)
     * @param scopedVertices true if graph nodes should be versioned and scoped
     * (different versions and/or scopes -> different nodes)
     *
     */

            if (versionRangeResult.getHighestVersion() == null) {
                throw new UnresolvableModelException(
                        String.format(
                                "No versions matched the requested parent version range '%s'", parent.getVersion()),
                        parent.getGroupId(),
                        parent.getArtifactId(),
                        parent.getVersion());
            }

    private ArtifactSpec createArtifactSpec(String id, String version) throws InvalidVersionSpecificationException {
        return createArtifactSpec(id, version, Artifact.SCOPE_COMPILE);
    }

    private ArtifactSpec createArtifactSpec(String id, String version, boolean optional)
            throws InvalidVersionSpecificationException {
        return createArtifactSpec(id, version, Artifact.SCOPE_COMPILE, null, optional);
    }