method MultiMapNonEmpty.prototype.modifyAtimport { MultiMapNonEmpty } from "https://deno.land/x/rimbu@0.14.1/multimap/custom/index.ts"; modifyAt(atKey: K, options: { ifNew?: OptLazy<StreamSource<V>>; ifExists?: (currentValues: TpG["keyMapValuesNonEmpty"]) => StreamSource<V>; }): TpG["normal"]ParametersatKey: Koptions: { ifNew?: OptLazy<StreamSource<V>>; ifExists?: (currentValues: TpG["keyMapValuesNonEmpty"]) => StreamSource<V>; }ReturnsTpG["normal"]