'Updates name and/or path of the specified user.
:type user_name: string
:param user_name: The name of the user
:type new_user_name: string
:param new_user_name: If provided, the username of the user will be
changed to this username.
:type new_path: string
:param new_path: If provided, the path of the user will be
changed to this path.'

def update_user(self, user_name, new_user_name=None, new_path=None):

    params = {'UserName': user_name}
    if new_user_name:
        params['NewUserName'] = new_user_name
    if new_path:
        params['NewPath'] = new_path
    return self.get_response('UpdateUser', params)
