class VCR::Cassette

def merged_interactions
  old_interactions = previously_recorded_interactions
  if should_remove_matching_existing_interactions?
    new_interaction_list = HTTPInteractionList.new(new_recorded_interactions, match_requests_on)
    old_interactions = old_interactions.reject do |i|
      new_interaction_list.response_for(i.request)
    end
  end
  if should_remove_unused_interactions?
    new_recorded_interactions
  else
    up_to_date_interactions(old_interactions) + new_recorded_interactions
  end
end