import { MultiMapEmpty } from "https://deno.land/x/rimbu@1.2.1/multimap/custom/implementation/base.ts";
Returns
WithKeyValue<Tp, K, V>["nonEmpty"]
x/rimbu/multimap/custom/implementation/base.ts>MultiMapEmpty#add
import { MultiMapEmpty } from "https://deno.land/x/rimbu@1.2.1/multimap/custom/implementation/base.ts";