def defaultname(name=None):
if name is None:<EOL><INDENT>name = _RESOLVER_REGISTRY.default<EOL><DEDENT>else:<EOL><INDENT>_RESOLVER_REGISTRY.default = name<EOL><DEDENT>return name<EOL>
Get default resolver name.

    :param str name: if given, change the default name.
    :raises: NameError if name given and not in registered resolvers.
    :rtype: str