return (string == null || string.isEmpty()) ? null : string;
    }

    public static org.apache.maven.artifact.Artifact toArtifact(Dependency dependency) {
        if (dependency == null) {
            return null;
        }

        org.apache.maven.artifact.Artifact result = toArtifact(dependency.getArtifact());
        result.setScope(dependency.getScope());
        result.setOptional(dependency.isOptional());

class RepositoryUtilsTest {

    @Test
    void testToArtifactMethodsReturnNullWhenInputParameterIsNull() {
        assertNull(RepositoryUtils.toArtifact((Dependency) null));
        assertNull(RepositoryUtils.toArtifact((Artifact) null));
        assertNull(RepositoryUtils.toArtifact((org.apache.maven.artifact.Artifact) null));
    }

        this.repoSystem = repoSystem;
        this.dependenciesValidators = dependenciesValidators;
    }

    private Artifact toArtifact(Plugin plugin, RepositorySystemSession session) {
        return new DefaultArtifact(
                plugin.getGroupId(),
                plugin.getArtifactId(),
                null,
                "jar",

            return delegate.pathOf(RepositoryUtils.toArtifact(artifact.setVersion(artifact.getBaseVersion())));
        }
        return delegate.pathOf(RepositoryUtils.toArtifact(artifact));
    }

    @Override
    public String getPathForRemoteArtifact(Artifact artifact, RemoteRepository repository, String context) {
        return delegate.pathOf(RepositoryUtils.toArtifact(artifact));
    }

    @Override

    }

    @Nonnull
    @Override
    public List<ProducedArtifact> getArtifacts() {
        org.eclipse.aether.artifact.Artifact pomArtifact = RepositoryUtils.toArtifact(new ProjectArtifact(project));
        org.eclipse.aether.artifact.Artifact projectArtifact = RepositoryUtils.toArtifact(project.getArtifact());

        ArrayList<ProducedArtifact> result = new ArrayList<>(2);
        result.add(session.getArtifact(ProducedArtifact.class, pomArtifact));

            }
            throw new IllegalArgumentException(message);
        }
        getMavenProject(project)
                .addAttachedArtifact(
                        RepositoryUtils.toArtifact(getSession(project).toArtifact(artifact)));
        artifactManager.setPath(artifact, path);
    }

    @Nonnull
    @Override
    public Collection<SourceRoot> getSourceRoots(@Nonnull Project project) {

        request.setTrace(RequestTrace.newChild(null, legacySupport.getSession().getCurrentProject()));

        org.eclipse.aether.artifact.Artifact mainArtifact = RepositoryUtils.toArtifact(artifact);
        mainArtifact = mainArtifact.setFile(source);
        request.addArtifact(mainArtifact);

        for (ArtifactMetadata metadata : artifact.getMetadataList()) {

        request.setTrace(RequestTrace.newChild(null, legacySupport.getSession().getCurrentProject()));

        org.eclipse.aether.artifact.Artifact mainArtifact = RepositoryUtils.toArtifact(artifact);
        mainArtifact = mainArtifact.setFile(source);
        request.addArtifact(mainArtifact);

        String versionKey = artifact.getGroupId() + ':' + artifact.getArtifactId();

                        delegate.getMojoDescriptor().getPluginDescriptor().getPluginArtifact();
                org.eclipse.aether.artifact.Artifact resolverArtifact = RepositoryUtils.toArtifact(artifact);
                return resolverArtifact != null ? session.getArtifact(resolverArtifact) : null;
            }

            @Override
            public Map<String, Dependency> getDependenciesMap() {

            if (decorated != null) {
                session = decorated;
            }
        }

        CollectRequest collect = new CollectRequest();
        collect.setRootArtifact(RepositoryUtils.toArtifact(project.getArtifact()));
        collect.setRequestContext("project");
        collect.setRepositories(project.getRemoteProjectRepositories());

        if (project.getDependencyArtifacts() == null) {