code: def namespaces(*prefixes):
      
      namespaces = {}
      for prefix in prefixes:
          namespaces[prefix] = _nsmap[prefix]
      return namespaces
docs: Return a dict containing the subset namespace prefix mappings specified by
      *prefixes*. Any number of namespace prefixes can be supplied, e.g.
      namespaces('a', 'r', 'p').