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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 get_custom_implementations(self):
 """Retrieve a list of cutom implementations. Yields: (str, str, ImplementationProperty) tuples: The name of the attribute an implementation lives at, the name of the related transition, and the related implementation. """

        for trname in self.custom_implems:
            attr = self.transitions_at[trname]
            implem = self.implementations[trname]
            yield (trname, attr, implem)