# File lib/aws/ec2/instance.rb, line 544
      def associate_elastic_ip elastic_ip

        client_opts = {}
        client_opts[:instance_id] = self.id

        if vpc?
          client_opts[:allocation_id] = elastic_ip.is_a?(ElasticIp) ?
            elastic_ip.allocation_id :
            elastic_ip.to_s
        else
          client_opts[:public_ip] = elastic_ip.to_s
        end

        client.associate_address(client_opts)
        nil

      end