class Rcov::DifferentialAnalyzer

def raw_data_relative
  case @cache_state
  when :wait
    return @aggregated_data
  when :hooked
    new_start = raw_data_absolute
    new_diff = compute_raw_data_difference(@start_raw_data, new_start)
    @start_raw_data = new_start
  when :done
    @cache_state = :wait
    new_diff = compute_raw_data_difference(@start_raw_data, 
                                           @end_raw_data)
  end
  aggregate_data(@aggregated_data, new_diff)
  @aggregated_data
end