a = a.setVersion(versionResult.getVersion());

                versionRequest =
                        new VersionRequest(pomArtifact, request.getRepositories(), request.getRequestContext());
                versionRequest.setTrace(trace);
                versionResult = versionResolver.resolveVersion(session, versionRequest);

                Objects.requireNonNull(repositoryEventDispatcher, "repositoryEventDispatcher cannot be null");
    }

    @SuppressWarnings("checkstyle:methodlength")
    @Override
    public VersionResult resolveVersion(RepositorySystemSession session, VersionRequest request)
            throws VersionResolutionException {
        RequestTrace trace = RequestTrace.newChild(request.getTrace(), request);

                Objects.requireNonNull(repositoryEventDispatcher, "repositoryEventDispatcher cannot be null");
    }

    @SuppressWarnings("checkstyle:methodlength")
    @Override
    public VersionResult resolveVersion(RepositorySystemSession session, VersionRequest request)
            throws VersionResolutionException {
        RequestTrace trace = RequestTrace.newChild(request.getTrace(), request);

    public VersionConstraint parseVersionConstraint(String versionConstraint) {
        return getService(VersionParser.class).parseVersionConstraint(versionConstraint);
    }

    @Override
    public Version resolveVersion(ArtifactCoordinate artifact) {
        return getService(VersionResolver.class).resolve(this, artifact).getVersion();
    }

    @Override
    public List<Version> resolveVersionRange(ArtifactCoordinate artifact) {

     *
     * @see org.apache.maven.api.services.VersionResolver#resolve(Session, ArtifactCoordinate) (String)
     */
    @Nonnull
    Version resolveVersion(@Nonnull ArtifactCoordinate artifact);

    /**
     * Expands a version range to a list of matching versions, in ascending order.
     * For example, resolves "[3.8,4.0)" to "3.8", "3.8.1", "3.8.2".