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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 save(self, sc, path):
 """Save an IsotonicRegressionModel."""

        java_boundaries = _py2java(sc, self.boundaries.tolist())
        java_predictions = _py2java(sc, self.predictions.tolist())
        java_model = sc._jvm.org.apache.spark.mllib.regression.IsotonicRegressionModel(
            java_boundaries, java_predictions, self.isotonic)
        java_model.save(sc._jsc.sc(), path)