function indexOfimport { indexOf } from "https://dotland.deno.dev/std@0.116.0/bytes/mod.ts"; indexOf(source: Uint8Array,pattern: Uint8Array,fromIndex?,): numberReturns the index of the first occurrence of the pattern array in the source array, or -1 if it is not present. Returns the index of the first occurrence of the pattern array in the source array, or -1 if it is not present. Parameterssource: Uint8Arraypattern: Uint8ArrayoptionalfromIndex = [UNSUPPORTED]Returnsnumber