function addToRangeimport { addToRange } from "https://deno.land/x/netzo@0.5.30/deps/react-day-picker.ts"; addToRange(day: Date, range?: DateRange): DateRange | undefinedAdd a day to an existing range. Add a day to an existing range. The returned range takes in account the undefined values and if the added day is already present in the range. Parametersday: Dateoptionalrange: DateRangeReturnsDateRange | undefined