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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 load_file(self, filename):
 """ load file which contains yaml configuration entries.and merge it by current instance :param files: files to load and merge into existing configuration instance :type files: list """

        if not path.exists(filename):
            raise FileNotFoundError(filename)

        loaded_yaml = load_yaml(filename, self.context)
        if loaded_yaml:
            self.merge(loaded_yaml)