import { Bson } from "https://deno.land/x/mongo@v0.31.0/mod.ts";
const { BufReader } = Bson;
reads data into p. It returns the number of bytes read into p. The bytes are taken from at most one Read on the underlying Reader, hence n may be less than len(p). To read exactly len(p) bytes, use io.ReadFull(b, p).