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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 match(self, ref):
 """ Get all concepts matching this ref. For a dimension, that is all its attributes, but not the dimension itself. """

        try:
            concept = self[ref]
            if not isinstance(concept, Dimension):
                return [concept]
            return [a for a in concept.attributes]
        except KeyError:
            return []