Get a "random" value
Being a deterministic blockchain, real randomness is difficult to come by. This gives you something that approximates it. At best, this will be randomness which was hard to predict a long time ago, but that has become easy to predict recently.
subject is a context identifier and allows you to get a
different result to other callers of this function; use it like
pub fn random_seed() -> Output
Get the basic random seed.
In general you won't want to use this, but rather
Self::random which allows you to give a
subject for the random result and whose value will be independently low-influence random
from any other such seeds.