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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 _merge(cls, default, user):
 """Append user options to default options. Return yala section."""

        section = cls._CFG_SECTION
        merged = default[section]

        if section not in user:
            return merged

        user = user[section]
        for key, value in user.items():
            if key in merged:
                merged[key] += ' ' + value
            else:
                merged[key] = value
        return merged