human
Solve the following python programming problem given the following code:
@ permissions (ADMIN) 
def list_users(email_prefix = '', cursor = None) : 
    cmd = facade.find_users_by_email_starting_with (email_prefix, cursor_str) 
    users = cmd.execute ().result 
    def to_dict(user) : 
        d = user.to_dict (include = ['id', 'email', 'name', 'groups']) 
        d ['update'] = router.to_path (update, user.key.id ()) 
        return d 
users = [to_dict (u) for u in users] 
    cursor_str = (cmd.cursor.urlsafe () if cmd.cursor else '') 
    next_page = router.to_path (list_users, email_prefix = email_prefix, cursor = cursor_str) 
    return JsonResponse ({ 
        'users' : users, 
        'next_page' : next_page, 
        'more' : cmd.more, 
}) 

    
    

    Fix the buggy line: cmd = facade.find_users_by_email_starting_with (email_prefix, cursor_str)
assistant
#Here is Python code to fix the buggy line: cmd = facade.

cmd = facade.find_users_by_email_starting_with (email_prefix, cursor)