fixed lint

Author: daniel-sanche

tests/unit/data/_metrics/test_data_model.py

@@ -12,7 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import time
 import pytest
 import mock
 
@@ -200,8 +199,6 @@ def test_start_attempt(self, mock_monotonic_ns):
         """
         from google.cloud.bigtable.data._metrics.data_model import ActiveAttemptMetric
 
-        from google.cloud.bigtable.data._metrics.data_model import ActiveAttemptMetric
-
         expected_timestamp = 123456789
         mock_monotonic_ns.return_value = expected_timestamp
         metric = self._make_one(mock.Mock())