title: How to generate an array of random bytes from a seed?
body: <p>I want to generate a UUID from a custom random number generator:</p>
  
  <pre><code>use uuid::{Builder, Uuid, Variant, Version};
  use rand::{Rng, SeedableRng, rngs::StdRng, RngCore};
  
  fn main() {
      let seed = [5u8; 32];
      let mut rng: StdRng = SeedableRng::from_seed(seed);
      let bytes = ???
      let uuid = Builder::from_bytes(bytes)
          .set_variant(Variant::RFC4122)
          .set_version(Version::Random)
          .build();
      println!("{:?}", uuid);
  }
  </code></pre>
  
  <p>How do I get the bytes?</p>