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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 add_nexusnve_binding(vni, switch_ip, device_id, mcast_group):
 """Adds a nexus nve binding."""

    LOG.debug("add_nexusnve_binding() called")
    session = bc.get_writer_session()
    binding = nexus_models_v2.NexusNVEBinding(vni=vni,
                                              switch_ip=switch_ip,
                                              device_id=device_id,
                                              mcast_group=mcast_group)
    session.add(binding)
    session.flush()
    return binding