hunk.code_window:     let subscription: Subscription;
       this.schedule(() => {
         subscription = observable.subscribe(
           (x) => {
             // Support Observable-of-Observables
             const value = x instanceof Observable ? this.materializeInnerObservable(x, this.frame) : x;
             actual.push({ frame: this.frame, notification: nextNotification(value) });
           },
  
hunk.labels: keep keep keep replace replace keep keep keep keep
hunk.after_edit:       subscription = observable.subscribe({
           next: (x) => {
  
hunk.file_path: src/internal/testing/TestScheduler.ts
hunk.type: replace
file: import { NEVER } from 'rxjs';
  import { expect } from 'chai';
  import { expectObservable } from '../helpers/marble-testing';
  
  /** @test {NEVER} */
  describe('NEVER', () => {
    it('should create a cold observable that never emits', () => {
      const expected = '-';
      const e1 = NEVER;
      expectObservable(e1).toBe(expected);
    });
  
    it('should return the same instance every time', () => {
      expect(NEVER).to.equal(NEVER);
    });
  });
  