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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 create_instance(self, port):
 """Enqueue instance create"""

        instance_type = self.get_instance_type(port)
        if not instance_type:
            return
        i_res = MechResource(port['device_id'], instance_type, a_const.CREATE)
        self.provision_queue.put(i_res)