message: warning if start is invoked before AudioContext is running
  addresses
diff: @@ -8,6 +8,7 @@ import { defaultArg } from "../core/util/Defaults";
  import { noOp, readOnly } from "../core/util/Interface";
  import { BasicPlaybackState, StateTimeline } from "../core/util/StateTimeline";
  import { isUndef } from "../core/util/TypeCheck";
  +import { assertContextRunning } from "../core/util/Debug";
  type onStopCallback = (source: Source<any>) => void;
  @@ -209,6 +210,7 @@ export abstract class Source<Options extends SourceOptions> extends ToneAudioNod
  } else {
  this._start(computedTime, offset, duration);
  }
  + assertContextRunning(this.context);
  }
  return this;
  }
  