project.children.size() == 1
        GradleProject a = project.children[0]
        a.name == 'a'
        a.path == ':a'
        a.description == 'A rocks!'

        a.children.size() == 2
        a.children.find { it.name == 'b' && it.path == ':a:b' }
        a.children.find { it.name == 'c' && it.path == ':a:c' }
        
        a.children.find { it.name == 'c'}.children[0].name == 'd'
    }

public abstract class AbstractIncompleteFileSystemNode implements FileSystemNode {
    protected final ChildMap<FileSystemNode> children;

    @SuppressWarnings("unchecked")
    public AbstractIncompleteFileSystemNode(ChildMap<? extends FileSystemNode> children) {
        this.children = (ChildMap<FileSystemNode>) children;
    }

    @Override

    }

    @Override
    public Set<ResourceFilterMatcher> getChildren() {
        return children;
    }

    public void setChildren(Set<ResourceFilterMatcher> children) {
        if (children == null) {
            throw new InvalidUserDataException("children must not be null");
        }
        this.children = children;
    }

     *          siblings of the dominant children.</li>
     *     <li> otherwise, use the default value for mergeChildren, which is true...this is the same as specifying
     *         'combine.children' == 'merge' as an attribute on the dominant root node.</li>
     *     </ol></li>
     *   <li> Iterate through the recessive children, and:
     *     <ol type="i">

                }

                children.add(new ResolutionNode(a, remoteRepositories, this));
            }
            children = Collections.unmodifiableList(children);
        } else {
            children = Collections.emptyList();
        }
        trail = null;
    }

    /**

        rootProject.parent == null

        rootProject.children.size() == 2
        def children = rootProject.children.sort { it.name }

        EclipseProject child1 = children[0]
        child1.name == 'child1'
        child1.parent == rootProject
        child1.children.size() == 1

        EclipseProject child1Child1 = child1.children[0]
        child1Child1.name == 'grandChild1'

    MetadataTreeNode parent; // papa

    /** default # of children. Used for tree creation optimization only */
    int nChildren = 8;

    MetadataTreeNode[] children; // of cause

    public int getNChildren() {
        return nChildren;
    }

    public void setNChildren(int children) {
        nChildren = children;
    }

 *
 * This implementation combines the hashes of the children of a directory into a single hash for the directory.
 * For the hash to be reproducible, the children must be sorted in a consistent order.
 * The implementation uses {@link FileSystemLocationSnapshot#BY_NAME} ordering.
 * If you already provide the children in sorted order, use {@link #noSortingRequired()} to avoid the overhead of sorting again.
 */

    private final ChildMap<FileSystemLocationSnapshot> children;
    private final HashCode contentHash;

    public DirectorySnapshot(String absolutePath, String name, AccessType accessType, HashCode contentHash, List<FileSystemLocationSnapshot> children) {
        this(absolutePath, name, accessType, contentHash, childMapFromSorted(children.stream()
            .map(it -> new ChildMap.Entry<>(it.getName(), it))

        verifyTaskDetails(RegisterTaskBuildOperationType, withPath(':', ':foo')).children.empty
        def realize = verifyTaskDetails(RealizeTaskBuildOperationType, withPath(':', ':foo'))
        realize.children.size() == 1
        def configure = realize.children[0]
        configure.children.size() == 1
        buildOperations.isType(configure.children[0], RealizeTaskBuildOperationType)