def METHOD_NAME(self, i):
    if isinstance(i, (int, int64)):
        i = [i]
    i = asarray(i)
    n = len(i)
    obj = RBE2(self.model)
    obj.element_id = self.element_id[i]
    obj.gn = self.gn[i]
    obj.cm = self.cm[i]
    obj.alpha = self.alpha[i]
    Gmi = {}
    j = 0
    for ii, gmi in self.gmi.items():
        #print(gmi)
        if ii in i:
            Gmi[j] = gmi
            j += 1
    obj.gmi = Gmi
    obj.n = n
    self.i = n