Uses class LGT to perform random lateral gene transfer on
        ultrametric tree

def rlgt(self, time=None, times=1,
             disallow_sibling_lgts=False):
        """ Uses class LGT to perform random lateral gene transfer on
        ultrametric tree """

        lgt = LGT(self.copy())
        for _ in range(times):
            lgt.rlgt(time, disallow_sibling_lgts)
        return lgt.tree