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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 find_config_file(self):
 """ Find where our config file is if there is any If the value for the config file is a default and it doesn't exist then it is silently ignored. If however, the value isn't a default and it doesn't exist, an error is raised """

        filename = self.values.get('config_file', Default('noy.json'))

        ignore_missing = False
        if isinstance(filename, Default):
            filename = filename.val
            ignore_missing = True

        filename = os.path.abspath(filename)
        if os.path.exists(filename):
            return filename
        elif not ignore_missing:
            raise MissingConfigFile("Config file doesn't exist at {}".format(filename))