def __init__(self, backend, username=None, user=None):
self.backend = backend<EOL>self._username = username<EOL>if user is not None:<EOL><INDENT>self._set_authenticated_user(user)<EOL><DEDENT>if username is None and user is None:<EOL><INDENT>raise Exception("<STR_LIT>")<EOL><DEDENT>
A new LDAPUser must be initialized with either a username or an
authenticated User object. If a user is given, the username will be
ignored.