diff --git a/city_model_structure/city.py b/city_model_structure/city.py
index 59476ecd..520d9e84 100644
--- a/city_model_structure/city.py
+++ b/city_model_structure/city.py
@@ -455,5 +455,5 @@ class City:
     return _merge_city
 
   @property
-  def level_of_detail(self):
+  def level_of_detail(self) -> LevelOfDetail:
       return self._level_of_detail
diff --git a/exports/building_energy/idf.py b/exports/building_energy/idf.py
index a56467d1..0d1ee196 100644
--- a/exports/building_energy/idf.py
+++ b/exports/building_energy/idf.py
@@ -119,6 +119,7 @@ class Idf:
       self._adjacent_buildings = []
     self._export()
 
+
   @staticmethod
   def _matrix_to_list(points, lower_corner):
     lower_x = lower_corner[0]
diff --git a/helpers/constants.py b/helpers/constants.py
index 630a71f9..77710265 100644
--- a/helpers/constants.py
+++ b/helpers/constants.py
@@ -6,7 +6,6 @@ Project Coder Pilar Monsalvete Alvarez de Uribarri pilar.monsalvete@concordia.ca
 """
 
 # universal constants
-import sys
 
 KELVIN = 273.15
 
diff --git a/unittests/test_geometry_factory.py b/unittests/test_geometry_factory.py
index c4cf667f..5da32682 100644
--- a/unittests/test_geometry_factory.py
+++ b/unittests/test_geometry_factory.py
@@ -150,7 +150,7 @@ class TestGeometryFactory(TestCase):
     """
     Test geojson import
     """
-    file = 'concordia.geojson'
+    file = 'sample.geojson'
     city = self._get_city(file, 'geojson',
                           height_field='citygml_me',
                           year_of_construction_field='ANNEE_CONS',