* artifact files.
     *
     * @param session the {@link Session}, must not be {@code null}
     * @param root the Maven Dependency, must not be {@code null}
     * @return the collection result, never {@code null}
     * @throws DependencyCollectorException if the dependency tree could not be built
     * @throws IllegalArgumentException if an argument is null or invalid

     * @param oldValue the expected data currently associated with the key, may be {@code null}
     * @param newValue the data to associate with the key, may be {@code null} to remove the mapping
     * @return {@code true} if the key mapping was successfully updated from the old value to the new value,

     * @return the parsed version constraint, never {@code null}
     * @throws VersionParserException if the range specification violates the syntax rules of this scheme
     */
    @Nonnull
    VersionConstraint parseVersionConstraint(@Nonnull String constraint);

    /**
     * Checks whether a given artifact version is considered a {@code SNAPSHOT} or not.
     */

     */
    Map<String, String> getUserProperties();

    /**
     * Gets the base directory of the current project (if any).
     *
     * @return The base directory of the current project or {@code null} if none.
     */
    Path getProjectDirectory();

    /**
     * Gets current calculated project properties
     *
     * @return The project properties, never {@code null}.
     */

     * @param message The detail message of the problem, may be {@code null}.
     * @param line The one-based index of the line containing the problem or {@code -1} if unknown.
     * @param column The one-based index of the column containing the problem or {@code -1} if unknown.
     * @param cause The cause of the problem, may be {@code null}.
     */

  <id>extension</id>
  <name>ExtensionDescriptor</name>
  <description><![CDATA[
    Extension descriptor, stored in <code>META-INF/maven/extension.xml</code> in an extension's jar artifact to
    precisely control parts of the extension and dependencies to expose in the API class loader.

+ Make commits of logical units.
+ Respect the original code style: by using the same [codestyle][code-style],
  patches should only highlight the actual difference, not being disturbed by any formatting issues:
  + Only use spaces for indentation.
  + Create minimal diffs - disable on save actions like reformat source code or organize imports.
    If you feel the source code should be reformatted, create a separate PR for this change.

    /**
     * Returns {@link Artifact} instance where to relocate to, or {@code null}.
     *
     * @param session The session, never {@code null}.
     * @param result The artifact descriptor result, never {@code null}.
     * @param model The artifact model, never {@code null}.
     * @return The {@link Artifact} to relocate to, or {@code null} if no relocation wanted.
     */

     *
     * @return The type of the event, never {@code null}.
     */
    Type getType();

    /**
     * Gets the session from which this event originates.
     *
     * @return The current session, never {@code null}.
     */
    MavenSession getSession();

    /**
     * Gets the current project (if any).
     *
     * @return The current project or {@code null} if not applicable.
     */

     *
     * @param versionRange The version range to match the current Maven runtime against, must not be {@code null}.
     * @return {@code true} if the current Maven runtime matches the specified version range, {@code false} otherwise.
     * @throws IllegalArgumentException If the specified version range is {@code null}, empty or otherwise not a valid
     *             version specification.
     */