code: def instance(self, root, baseurl, loaded_schemata, options):
          
          return Schema(root, baseurl, options, loaded_schemata)
docs: Create and return an new schema object using the specified I{root} and
          I{URL}.
  
          @param root: A schema root node.
          @type root: L{sax.element.Element}
          @param baseurl: A base URL.
          @type baseurl: str
          @param loaded_schemata: Already loaded schemata cache (URL --> Schema).
          @type loaded_schemata: dict
          @param options: An options dictionary.
          @type options: L{options.Options}
          @return: The newly created schema object.
          @rtype: L{Schema}
          @note: This is only used by Import children.