*
     * @param project {@link Project} or {@code null}.
     * @return the effective properties, never {@code null}
     */
    @Nonnull
    Map<String, String> getEffectiveProperties(@Nullable Project project);

    /**
     * Returns the current maven version
     * @return the maven version, never {@code null}
     */
    @Nonnull
    Version getMavenVersion();

    int getDegreeOfConcurrency();

        // have a model that is suitable, yet more checks are done here and the one for the version is problematic
        // before because with parents as ranges it will never work in this scenario.
        //

        String groupId = getGroupId(candidateModel);
        String artifactId = candidateModel.getArtifactId();

        if (groupId == null

     * @param parent The parent coordinates to resolve, must not be {@code null}.
     * @param modified a holder for the updated parent, must not be {@code null}.
     * @return The source of the requested POM, never {@code null}.
     * @throws ModelResolverException If the POM could not be resolved from any configured repository.
     */
    @Nonnull
    default ModelSource resolveModel(