message: asserts that the buffer should be loaded when trying to slice
  addresses
diff: @@ -240,6 +240,7 @@ export class ToneAudioBuffer extends Tone {
  * @param end The end time to slice. If none is given will default to the end of the buffer
  */
  slice(start: Seconds, end: Seconds = this.duration): ToneAudioBuffer {
  + assert(this.loaded, "Buffer is not loaded");
  const startSamples = Math.floor(start * this.sampleRate);
  const endSamples = Math.floor(end * this.sampleRate);
  assert(startSamples < endSamples, "The start time must be less than the end time");
  