**Julia version**

`Julia 1.0.5`

**What I want to do:**

I want to draw a random sample from a continuous uniform distribution, U[10, 50].

**A way to do it in Julia**

The following works:

```
import Distributions
unifdist = Distributions.Uniform(10, 50)
sample_size_1 = Distributions.rand(unifdist)
sample_size_5 = Distributions.rand(unifdist, 5)
```

**Question**

If I run `methods(Distributions.rand)`

150 methods come up. Searching for Uniform brings up:

`rand(rng::Random.AbstractRNG, d::Distributions.Uniform)`

What I don’t understand is that why the above code example works when I am not passing the first argument. It does not show up as optional in this list of methods. I also searched in the list of methods for the term `UnivariateDistribution`

, thinking that UniformDistribution is a subtype of `UnivariateDistribution`

. But there is no method that comes up that shows `rng`

as optional, or even shows that the number of sampled observations can be entered as an optional argument.

What am I missing? How could I have figured from the documentation (or methods list) that the above code examples are possible?

Thank you. I appreciate your help.