import { type UpgradeWebSocketFn } from "https://deno.land/x/oak@v17.1.2/types.ts";
definition: (request: Request, options?: UpgradeWebSocketOptions) => WebSocketUpgrade
x/oak/types.ts>UpgradeWebSocketFn
import { type UpgradeWebSocketFn } from "https://deno.land/x/oak@v17.1.2/types.ts";