code: public void addMilestones(@NonNull List<Milestone> milestones) {
      boolean milestonesAdded = this.milestones.addAll(milestones);
      if (!milestonesAdded) {
        Timber.w("These milestones have already been added to the stack.");
      }
    }
docs: Adds the given list of {@link Milestone} to be triggered during navigation.
  <p>
  Milestones can only be added once and must be removed and added back if any changes are
  desired.
  </p>
  
  @param milestones a list of custom built milestone
  @since 0.14.0