is GeneratedSingletonFileTree -> GeneratedTreeSpec(tree.toSpec())
        is DirectoryFileTree -> DirectoryTreeSpec(tree.dir, tree.patternSet)
        else -> null
    }

    private
    fun cannotCreateSpecFor(tree: MinimalFileTree): Nothing =
        throw UnsupportedOperationException("Cannot create spec for file tree '$tree' of type '${tree.javaClass}'.")

    FileTreeInternal treeOf(List<? extends FileTreeInternal> fileTrees);

    FileTreeInternal treeOf(MinimalFileTree tree);

    static FileTreeInternal emptyTree() {
        return EmptyFileTree.INSTANCE;
    }

    static FileTreeInternal emptyTree(String displayName) {
        if (FileTreeInternal.DEFAULT_TREE_DISPLAY_NAME.equals(displayName)) {
            return emptyTree();
        } else {

            return new DefaultCompositeFileTree(taskDependencyFactory, patternSetFactory, ImmutableList.copyOf(fileTrees));
        }
    }

    @Override
    public FileTreeInternal treeOf(MinimalFileTree tree) {
        return new FileTreeAdapter(tree, listener, taskDependencyFactory, patternSetFactory);
    }

    @Override
    public FileCollectionInternal create(TaskDependency builtBy, MinimalFileSet contents) {

            walk(copySpecResolver -> builder.add(Cast.<FileTreeInternal>uncheckedCast(copySpecResolver.getSource())));
            return fileCollectionFactory.treeOf(builder.build());
        }

        @Override
        public Collection<? extends Action<? super FileCopyDetails>> getAllCopyActions() {
            if (parentResolver == null) {
                return copyActions;

file-collection-vs-file-tree.png...

env GIT_COMMITTER_DATE=2024-01-30T10:53:00+08:00
env GIT_AUTHOR_DATE=2024-01-30T10:53:00+08:00
exec git add extra.go
exec git commit -m 'add extra.go'

# Assume the tree object from initial commit is not available (e.g. partial clone)
exec git log --pretty=%T
cmp stdout $WORK/.git-trees

rm .git/objects/66/400c89b45cc96da36d232844dbf9ea5daa6bcf

# Build the module, which should succeed
go build -v -buildvcs=true -o test
go version -m test

func (t *Template) AddParseTree(name string, tree *parse.Tree) (*Template, error) {
	t.init()
	t.muTmpl.Lock()
	defer t.muTmpl.Unlock()
	nt := t
	if name != t.name {
		nt = t.New(name)
	}
	// Even if nt == t, we need to install it in the common.tmpl map.
	if t.associate(nt, tree) || nt.Tree == nil {
		nt.Tree = tree
	}
	return nt, nil
}

	// order to minimize the amount of information needed to build a tree
	// bzip2 uses a canonical tree so that it can be reconstructed given
	// only the code length assignments.

	if len(lengths) < 2 {
		panic("newHuffmanTree: too few symbols")
	}

	var t huffmanTree

	// First we sort the code length assignments by ascending code length,
	// using the symbol value to break ties.

	XTestImports []string `yaml:",omitempty"` // imports from XTestGoFiles
}

// ImportRestriction describes a set of allowable import
// trees for a tree of source code
type ImportRestriction struct {
	// BaseDir is the root of a package tree that is restricted by this
	// configuration, given as a relative path from the root of the repository.
	// This is a directory which `go list` might not consider a package (if it

// The receiver is only used when the node does not have a pointer to the tree inside,
// which can occur in old code.
func (t *Tree) ErrorContext(n Node) (location, context string) {
	pos := int(n.Position())
	tree := n.tree()
	if tree == nil {
		tree = t
	}
	text := tree.text[:pos]
	byteNum := strings.LastIndex(text, "\n")
	if byteNum == -1 {
		byteNum = pos // On first line.