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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 reset_defaults(self, config_file):
 """Reset defaults. """

        if not exists(config_file):
            err_exit('No such file: %(config_file)s' % locals())
        if not isfile(config_file):
            err_exit('Not a file: %(config_file)s' % locals())
        if not os.access(config_file, os.R_OK):
            err_exit('File cannot be read: %(config_file)s' % locals())
        self.set_defaults(config_file)