diff --git a/force_bdss/core_plugins/dummy_kpi/kpi_adder/kpi_adder_model.py b/force_bdss/core_plugins/dummy_kpi/kpi_adder/kpi_adder_model.py
index 3d57563f9444cde1c31175193b8b03ca3b275d85..099c422f80070ed3b8bb844cdd0c01bb3a6e628f 100644
--- a/force_bdss/core_plugins/dummy_kpi/kpi_adder/kpi_adder_model.py
+++ b/force_bdss/core_plugins/dummy_kpi/kpi_adder/kpi_adder_model.py
@@ -6,10 +6,3 @@ from force_bdss.api import BaseKPICalculatorModel
 class KPIAdderModel(BaseKPICalculatorModel):
     cuba_type_in = String()
     cuba_type_out = String()
-
-    @classmethod
-    def from_json(cls, json_data):
-        return cls(
-            cuba_type_in=json_data["cuba_type_in"],
-            cuba_type_out=json_data["cuba_type_out"]
-        )
diff --git a/force_bdss/io/__init__.py b/force_bdss/io/__init__.py
new file mode 100644
index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
diff --git a/force_bdss/io/tests/__init__.py b/force_bdss/io/tests/__init__.py
new file mode 100644
index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
diff --git a/force_bdss/io/tests/test_workflow_reader.py b/force_bdss/io/tests/test_workflow_reader.py
new file mode 100644
index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391