diff --git a/force_bdss/core_plugins/dummy/dummy_dakota/tests/test_dakota_optimizer.py b/force_bdss/core_plugins/dummy/dummy_dakota/tests/test_dakota_optimizer.py
index e8025eda3121c6b2f8e40c16138b70c03393347c..6e1bf6223ee0e0a23144f8fd2ae8d1bea3eba55e 100644
--- a/force_bdss/core_plugins/dummy/dummy_dakota/tests/test_dakota_optimizer.py
+++ b/force_bdss/core_plugins/dummy/dummy_dakota/tests/test_dakota_optimizer.py
@@ -30,7 +30,8 @@ class TestDakotaOptimizer(unittest.TestCase):
         opt = DummyDakotaOptimizer(self.bundle)
         model = DummyDakotaModel(self.bundle)
         model.parameters = [
-            RangedMCOParameter(mock.Mock(spec=RangedMCOParameterFactory),
+            RangedMCOParameter(
+                mock.Mock(spec=RangedMCOParameterFactory),
                 lower_bound=1,
                 upper_bound=3,
                 initial_value=2)
diff --git a/force_bdss/data_sources/i_data_source_bundle.py b/force_bdss/data_sources/i_data_source_bundle.py
index cad0857442fd70406d6a1c6cf6ff8270fbcd90fe..0f803e3b8ae7f68445b71f643d0c5a1f614ada68 100644
--- a/force_bdss/data_sources/i_data_source_bundle.py
+++ b/force_bdss/data_sources/i_data_source_bundle.py
@@ -15,11 +15,7 @@ class IDataSourceBundle(Interface):
     plugin = Instance(Plugin)
 
     def create_data_source(self):
-        """Factory method.
-        Must return the bundle-specific BaseDataSource instance.
-        """
+        """"""
 
     def create_model(self, model_data=None):
-        """Factory method.
-        Must return the bundle-specific BaseDataSourceModel instance.
-        """
+        """"""
diff --git a/force_bdss/kpi/i_kpi_calculator_bundle.py b/force_bdss/kpi/i_kpi_calculator_bundle.py
index df71c49477ad76d4015ce81b15046a4d42198e70..2c32b24f72316d44d452af211cf41151cd680256 100644
--- a/force_bdss/kpi/i_kpi_calculator_bundle.py
+++ b/force_bdss/kpi/i_kpi_calculator_bundle.py
@@ -15,7 +15,7 @@ class IKPICalculatorBundle(Interface):
     plugin = Instance(Plugin)
 
     def create_kpi_calculator(self):
-        pass
+        """"""
 
     def create_model(self, model_data=None):
-        pass
+        """"""
diff --git a/force_bdss/mco/i_mco_bundle.py b/force_bdss/mco/i_mco_bundle.py
index 644f2b988d49e7d9064cb9085dbf205b539f15ec..8c6afcef40dc23c4d8ca1a1f7169a22f52752ba6 100644
--- a/force_bdss/mco/i_mco_bundle.py
+++ b/force_bdss/mco/i_mco_bundle.py
@@ -15,10 +15,10 @@ class IMCOBundle(Interface):
     plugin = Instance(Plugin)
 
     def create_optimizer(self):
-        pass
+        """"""
 
     def create_model(self, model_data=None):
-        pass
+        """"""
 
     def create_communicator(self):
-        pass
+        """"""