Return true that this model uses pm.sample

[canyon289]

with pm.Model():
    x = [pm.Normal](https://www.pymc.io/projects/docs/en/stable/api/distributions/generated/pymc.Normal.html#pymc.Normal)("x", mu=0, sigma=1)
    y = [pm.Gamma](https://www.pymc.io/projects/docs/en/stable/api/distributions/generated/pymc.Gamma.html#pymc.Gamma)("y", alpha=1, beta=1)
    plus_2 = x + 2
    summed = x + y
    squared = x**2
    sined = [pm.math.sin](https://www.pymc.io/projects/docs/en/stable/api/generated/pymc.math.sin.html#pymc.math.sin)(x)
    pm.sample()