arrays = Promise.all(
Object.entries(writers).map(async ([w, paths]) => {
let store = new zarr.FetchStore(new URL(w, baseUrl));
let grp = await zarr.open(store, { kind: "group" });
return Promise.all(
paths.map((p) => zarr.open(grp.resolve(p), { kind: "array" }))
);
})
).then((arr) => arr.flat())