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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 is_estimator(model):
 """ Determines if a model is an estimator using issubclass and isinstance. Parameters estimator : class or instance The object to test if it is a Scikit-Learn clusterer, especially a Scikit-Learn estimator or Yellowbrick visualizer """

    if inspect.isclass(model):
        return issubclass(model, BaseEstimator)

    return isinstance(model, BaseEstimator)