def tail_avg(timeseries):
    try:
        t = (timeseries[-1][1] + timeseries[-2][1] + timeseries[-3][1]) / 3
        return t
    except IndexError:
        return timeseries[-1][1]
iterate on all members and check if any has joined the replica
dataset/ETHPy150Open etsy/skyline/src/analyzer/algorithms.py/tail_avg--crossover with--dataset/ETHPy150Open mongolab/mongoctl/mongoctl/objects/replicaset_cluster.py/ReplicaSetCluster.is_replicaset_initialized