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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 unassign_floating_ip(self, ip_addr):
 """ Unassign a Floating IP from a Droplet. The Floating IP will be reserved in the region but not assigned to a Droplet. """

        if self.api_version == 2:
            params = {'type': 'unassign'}

            json = self.request('/floating_ips/' + ip_addr + '/actions', params=params, method='POST')
            return json['action']
        else:
            raise DoError(v2_api_required_str)