return FileType.Directory;
        }

        @Override
        public FileSystemNode asFileSystemNode() {
            return PartialDirectoryNode.withoutKnownChildren();
        }
    };

    /**
     * The type of the file.
     */
    FileType getType();

    FileSystemNode asFileSystemNode();

        )
        newChild.snapshot.get().type == FileType.Directory

        addedNodes == [newGrandChild]
        removedNodes.empty

        1 * snapshot.asFileSystemNode() >> newGrandChild
        _ * newGrandChild.snapshot >> Optional.of(snapshot)
        _ * selectedChild.snapshot >> Optional.empty()
        1 * snapshot.type >> fileType
        interaction { noMoreInteractions() }

            }

            @Override
            public FileSystemNode handleAsAncestorOfChild(String childPath, FileSystemNode child) {
                FileSystemNode newChild = snapshot.asFileSystemNode();
                diffListener.nodeRemoved(child);
                diffListener.nodeAdded(newChild);
                return newChild;
            }

            @Override

        VfsRelativePath relativePath = VfsRelativePath.of(absolutePath);
        if (relativePath.isEmpty()) {
            return new DefaultSnapshotHierarchy(snapshot.asFileSystemNode(), caseSensitivity);
        }
        return new DefaultSnapshotHierarchy(
            rootNode.store(relativePath, caseSensitivity, snapshot, diffListener),
            caseSensitivity
        );
    }

        return Stream.of(this);
    }

    @Override
    public boolean hasDescendants() {
        return true;
    }

    @Override
    public FileSystemNode asFileSystemNode() {
        return this;
    }

    @Override
    public Optional<MetadataSnapshot> getSnapshot() {
        return Optional.of(this);
    }

    @Override

        return new DirectorySnapshot("/root/some/path", PathUtil.getFileName("path"), AccessType.DIRECT, TestHashCodes.hashCodeFrom(1234), children).asFileSystemNode()
    }

    @Override
    protected FileSystemLocationSnapshot mockChild() {
        Mock(FileSystemLocationSnapshot)
    }

        when:
        def newHierarchy = hierarchy.store("/", snapshot, SnapshotHierarchy.NodeDiffListener.NOOP)
        then:
        1 * snapshot.asFileSystemNode() >> newRoot
        0 * _

        when:
        def foundSnapshot = newHierarchy.findMetadata("/")
        then:
        foundSnapshot.get() is snapshot