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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 _get_neighbor_conf(neigh_ip_address):
 """Returns neighbor configuration for given neighbor ip address. Raises exception if no neighbor with `neigh_ip_address` exists. """

    neigh_conf = \
        CORE_MANAGER.neighbors_conf.get_neighbor_conf(neigh_ip_address)
    if not neigh_conf:
        raise RuntimeConfigError(desc='No Neighbor configuration with IP'
                                 ' address %s' % neigh_ip_address)
    assert isinstance(neigh_conf, NeighborConf)
    return neigh_conf