public MetadataTreeNode getParent() {
        return parent;
    }

    public void setParent(MetadataTreeNode parent) {
        this.parent = parent;
    }

    public MetadataTreeNode[] getChildren() {
        return children;
    }

    public void setChildren(MetadataTreeNode[] children) {
        this.children = children;
    }

    entry.updateChild("file1.txt", attrs);
    
    assertTrue(entry.hasChild("file1.txt"));
    assertEquals(1, entry.getChildren().size());
    
    // Test removal
    entry.removeChild("file1.txt");
    assertFalse(entry.hasChild("file1.txt"));
    assertEquals(0, entry.getChildren().size());
}

@Test
public void testDirectoryLeaseManager() {

        Set<Artifact> artifacts = new LinkedHashSet<>();
        if (result.getDependencyGraph() != null
                && !result.getDependencyGraph().getChildren().isEmpty()) {
            RepositoryUtils.toArtifacts(
                    artifacts,
                    result.getDependencyGraph().getChildren(),
                    Collections.singletonList(project.getArtifact().getId()),
                    collectionFilter);
        }

            addEdge(parentVertex, vertex, e);
        } else {
            entry = vertex;
        }

        MetadataTreeNode[] kids = node.getChildren();
        if (kids == null || kids.length < 1) {
            return;
        }

        for (int i = 0; i < kids.length; i++) {
            MetadataTreeNode n = kids[i];

        Vertex(String label) {
            this.label = label;
        }

        String getLabel() {
            return label;
        }

        List<Vertex> getChildren() {
            return children;
        }

        List<Vertex> getParents() {
            return parents;
        }
    }

    static class CycleDetectedException extends RuntimeException {

    /**
     * Gets the children of this result.
     *
     * @return the children of this result, can be empty but never {@code null}
     */
    @Nonnull
    List<? extends ModelBuilderResult> getChildren();

    /**
     * Creates a human-readable representation of these errors.
     */
    @Override
    String toString();

        collectRequest.addRepository(newTestRepository());

        CollectResult collectResult = system.collectDependencies(session, collectRequest);

        List<DependencyNode> nodes = collectResult.getRoot().getChildren();
        assertEquals(2, nodes.size());
        checkUtSimpleArtifactDependencies(
                nodes.get(0).getDependency(), nodes.get(1).getDependency());
    }

    @Test

        }
    }

    private Set<String> getUnknownParameters(MojoExecution mojoExecution, Set<String> parameters) {
        return stream(mojoExecution.getConfiguration().getChildren())
                .map(Xpp3Dom::getName)
                .filter(name -> !parameters.contains(name))
                .collect(Collectors.toSet());
    }

        XmlNode toXml(PlexusConfiguration config, ExpressionEvaluator evaluator) throws ExpressionEvaluationException {
            List<XmlNode> children = new ArrayList<>();
            for (PlexusConfiguration c : config.getChildren()) {
                children.add(toXml(c, evaluator));
            }
            String name = config.getName();
            Object value = evaluator.evaluate(config.getValue());

        PlexusConfiguration c = mojoDescriptor.getMojoConfiguration();

        List<XmlNode> children = new ArrayList<>();
        PlexusConfiguration[] ces = c.getChildren();
        if (ces != null) {
            for (PlexusConfiguration ce : ces) {
                String value = ce.getValue(null);
                String defaultValue = ce.getAttribute("default-value", null);