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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 find_by_tag(self, tag) -> Dict[str, Set[Parameter]]: """ Get all registered dicts that are registered for a tag :param tag: str - single tag :return: a dict of {param name: set[Parameter]} that contains all ParameterScenarioSets for all parameter names with a given tag """

        return self.tags[tag]