message: test: correct misleading test description
diff: @@ -150,7 +150,7 @@ describe('single operator', () => {
  });
  });
  - it('should return undefined from predicate if observable does not contain matching element', () => {
  + it('should raise error from predicate if observable does not contain matching element', () => {
  rxTest.run(({ hot, expectObservable, expectSubscriptions }) => {
  const e1 = hot(' --a--b--c--|');
  const e1subs = ' ^----------!';
  