hunk.code_window:  * More than one input Observables may be given as argument.
    * @param {SchedulerLike} [scheduler=null] An optional {@link SchedulerLike} to schedule each
    * Observable subscription on.
  
hunk.labels: keep replace keep
hunk.after_edit:  * @param scheduler An optional {@link SchedulerLike} to schedule each
  
hunk.file_path: src/internal/observable/concat.ts
hunk.type: replace
file: {% extends 'var.template.html' -%}