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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 paid_totals_for(self, year, month):
 		"""Return paid Charges during a certain year, month with total amount, fee and refunded annotated."""

		return (
			self.during(year, month)
			.filter(paid=True)
			.aggregate(
				total_amount=models.Sum("amount"), total_refunded=models.Sum("amount_refunded")
			)
		)