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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 make_key(self, *parts):
 """Generate a namespaced key for the given path."""

        separator = getattr(self.model_class, 'index_separator', '.')
        parts = map(decode, parts)
        return '%s%s' % (self._base_key, separator.join(map(str, parts)))