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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_many(self, keys):
 # type: (Iterable[Hashable]) -> Promise """ Loads multiple keys, promising an array of values This is equivalent to the more verbose: """

        if not isinstance(keys, Iterable):
            raise TypeError(
                (
                    "The loader.loadMany() function must be called with Array<key> "
                    + "but got: {}."
                ).format(keys)
            )

        return Promise.all([self.load(key) for key in keys])