What happens if I don't pass new names to pyro.sample?

In the intro tutorial it says that we must make sure to pass unique names to pyro.sample() when creating geometric distribution as in:

def geometric(p, t=None):
if t is None:
    t = 0
x = pyro.sample("x_{}".format(t), pyro.distributions.Bernoulli(p))
if x.item() == 1:
    return 0
else:
    return 1 + geometric(p, t + 1)

print(geometric(0.5))

My question is: what’s the point of passing new names? it works just as well when passing same name. No explanation is provided in the tutorial.

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