Return list of SentinelGranule objects.

def granules(self):
        """Return list of SentinelGranule objects."""
        for element in self._product_metadata.iter("Product_Info"):
            product_organisation = element.find("Product_Organisation")
        if self.product_format == 'SAFE':
            return [
                SentinelGranule(_id.find("Granules"), self)
                for _id in product_organisation.findall("Granule_List")
                ]
        elif self.product_format == 'SAFE_COMPACT':
            return [
                SentinelGranuleCompact(_id.find("Granule"), self)
                for _id in product_organisation.findall("Granule_List")
                ]
        else:
            raise Exception(
                "PRODUCT_FORMAT not recognized in metadata file, found: '" +
                str(self.safe_format) +
                "' accepted are 'SAFE' and 'SAFE_COMPACT'"
            )