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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 update_customer(self, customer_id, **kwargs):
 		"""Update a customer."""

		body = self._formdata(kwargs, FastlyCustomer.FIELDS)
		content = self._fetch("/customer/%s" % customer_id, method="PUT", body=body)
		return FastlyCustomer(self, content)