Add. Store a class variable that contains a default time range for metric objects `DEFAULT_DATA_RANGE`
Add. Store a class variable that contains a default time range for metric objects `DEFAULT_DATA_RANGE`

wikimedia/analytics-user-metrics,wikimedia/user_metrics,wikimedia/analytics-user-metrics,rfaulkner/wikipedia_user_metrics,wikimedia/user_metrics,rfaulkner/wikipedia_user_metrics,wikimedia/user_metrics,rfaulkner/wikipedia_user_metrics,wikimedia/analytics-user-metrics