def new_metadata(name=None, authors=None, license=None, created=None,
    modified=None, gistid=None):
    """Create a new metadata node."""
    metadata = NotebookNode()
    if name is not None:
        metadata.name = unicode(name)
    if authors is not None:
        metadata.authors = list(authors)
    if created is not None:
        metadata.created = unicode(created)
    if modified is not None:
        metadata.modified = unicode(modified)
    if license is not None:
        metadata.license = unicode(license)
    if gistid is not None:
        metadata.gistid = unicode(gistid)
    return metadata