diff --git a/analytics/analytics/analytic_types/__init__.py b/analytics/analytics/analytic_types/__init__.py
index 011f47c..205b50f 100644
--- a/analytics/analytics/analytic_types/__init__.py
+++ b/analytics/analytics/analytic_types/__init__.py
@@ -1,6 +1,6 @@
 """
 It is the place where we put all classes and types
-which is common for all of the code.
+common for all analytics code
 
 For example, if you write someting which is used
 in analytic_unit_manager, it should be here.
@@ -8,11 +8,10 @@ in analytic_unit_manager, it should be here.
 If you create something spicific which is used only in one place, 
 like PatternDetectionCache, then it should not be here.
 """
+
 import pandas as pd
 from typing import Union, List
 
-from analytic_types.data_bucket import DataBucket
-
 AnalyticUnitId = str
 
 
diff --git a/analytics/analytics/analytic_types/data_bucket.py b/analytics/analytics/analytic_types/data_bucket.py
index 0561872..5eb3809 100644
--- a/analytics/analytics/analytic_types/data_bucket.py
+++ b/analytics/analytics/analytic_types/data_bucket.py
@@ -1,9 +1,7 @@
 import pandas as pd
 
 
-class DataBucket(object):
-
-    data: pd.DataFrame
+class DataBucket:
 
     def __init__(self):
         self.data = pd.DataFrame([], columns=['timestamp', 'value'])
diff --git a/analytics/analytics/detectors/pattern_detector.py b/analytics/analytics/detectors/pattern_detector.py
index 23e565b..caaa053 100644
--- a/analytics/analytics/detectors/pattern_detector.py
+++ b/analytics/analytics/detectors/pattern_detector.py
@@ -8,7 +8,7 @@ import pandas as pd
 from typing import Optional, Generator, List
 
 from detectors import Detector
-from analytic_types import DataBucket
+from analytic_types.data_bucket import DataBucket
 from models import ModelCache
 from utils import convert_pd_timestamp_to_ms
 from analytic_types import AnalyticUnitId