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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 datasets(self):
 """Method returns a list of dataset paths. Examples -------- print(dataset) '/dataset1/data1/data' '/dataset1/data2/data' '/dataset2/data1/data' '/dataset2/data2/data' """

        HiisiHDF._clear_cache()
        self.visititems(HiisiHDF._is_dataset)
        return HiisiHDF.CACHE['dataset_paths']