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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def exists(provider, config_location=DEFAULT_CONFIG_DIR):
 """Check whether provider info is already stored """


    config_dir = os.path.join(config_location, NOIPY_CONFIG)
    auth_file = os.path.join(config_dir, provider)
    return os.path.exists(auth_file)