pub fn load_shard(
path: &Path,
spec: &DrawSpec,
shard: Option<Shard>,
) -> Result<Vec<Sample>>Expand description
2026-09-26: Loads one shard of the draw, or all of it when shard is
None. The plan decides how many rows of each subset the draw takes, and
the shard then keeps every count-th of those; filtering before the plan
would change which rows the draw contains. An empty selection is an error.