<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def has_credentials_stored():
 """ Return 'auth token' string, if the user credentials are already stored """


    try:
        with open(credentials_file, 'r') as f:
            token = f.readline().strip()
            id = f.readline().strip()

            return token
    except Exception, e:
        return False