message: chore: remove useless import
diff: @@ -3,7 +3,6 @@ import { Observable } from './Observable';
  import { empty } from './observable/empty';
  import { of } from './observable/of';
  import { throwError } from './observable/throwError';
  -import { deprecate } from 'util';
  // TODO: When this enum is removed, replace it with a type alias. See #4556.
  /**
  