def get_first_timestamps_for_service_calls(self):
    scft = self._get_service_call_first_timestamps_collection()
    print((datetime.datetime.now().strftime('%H:%M:%s') + ' get_first_timestamps_for_service_calls_start1 '))
    results = []
    results_tmp = scft.find()
    print((datetime.datetime.now().strftime('%H:%M:%s') + ' get_first_timestamps_for_service_calls_start2 '))
    for item_tmp in results_tmp:
        results.append(item_tmp)
    print((datetime.datetime.now().strftime('%H:%M:%s') + ' get_first_timestamps_for_service_calls_end '))
    if (len(results) == 0):
        return pd.DataFrame()
    data = pd.DataFrame(results).drop('_id', axis=1)
    for col in ['first_request_timestamp', 'first_model_train_timestamp', 'first_incident_timestamp', 'first_model_retrain_timestamp']:
        data.loc[:, col] = pd.to_datetime(data.loc[:, col])
    return data
def get_first_timestamps_for_service_calls(self):
    scft = self._get_service_call_first_timestamps_collection()
    print((datetime.datetime.now().strftime('%H:%M:%s') + ' get_first_timestamps_for_service_calls_start1 '))
    results = []
    results_tmp = scft.find()
    print((datetime.datetime.now().strftime('%H:%M:%s') + ' get_first_timestamps_for_service_calls_start2 '))
    for item_tmp in results_tmp:
        results.append(item_tmp)
    print((datetime.datetime.now().strftime('%H:%M:%s') + ' get_first_timestamps_for_service_calls_end '))
    if (len(results) == 0):
        return pd.DataFrame()
    data = pd.DataFrame(results).drop('_id', axis=1)
    for col in ['first_request_timestamp', 'first_model_train_timestamp', 'first_incident_timestamp', 'first_model_retrain_timestamp']:
        data.loc[:, col] = pd.to_datetime(data.loc[:, col])
    return data