message: test that a warning is fired
diff: import { expect } from "chai";
  +import { warns } from "test/helper/Basic";
  import { Offline } from "test/helper/Offline";
  import { PassAudio } from "test/helper/PassAudio";
  import { Oscillator } from "Tone/source/oscillator/Oscillator";
  @@ -42,6 +43,13 @@ describe("Destination", () => {
  });
  });
  + it("warns when toMaster is called", () => {
  + warns(() => {
  + const osc = new Oscillator().toMaster();
  + osc.dispose();
  + });
  + });
  +
  it("can pass audio through chained nodes", () => {
  return PassAudio(input => {
  const gain = input.context.createGain();
  