Gets the [class@Dex.
Future] at position within this.
It is a programmer error to request a `DexFuture` which is outside of the range of the number of futures contained within the this. Use [method@Dex.FutureSet.get_size] to determine the number of `DexFuture` that are contained within the [class@Dex.FutureSet].
| this |
a [class@Dex.FutureSet] |
| position |
the position within the this |
|
the [class@Dex.Future] at |