diff --git a/calculation/calculation_rule.py b/calculation/calculation_rule.py
index 6fa1374..d2ee88c 100644
--- a/calculation/calculation_rule.py
+++ b/calculation/calculation_rule.py
@@ -10,6 +10,7 @@
 from policyholder.models import PolicyHolderInsuree
 from uuid import UUID
 
+
 class ContributionValuationRule(AbsStrategy):
     version = 1
     uuid = "0e1b6dd4-04a0-4ee6-ac47-2a99cfa5e9a8"
@@ -112,7 +113,6 @@ def calculate(cls, instance, **kwargs):
                     ))
                 else:
                     return [instance.contract_details.insuree]
-
             elif context == 'validity':
                 validity_from = kwargs.get('validity_from', None)
                 validity_to = kwargs.get('validity_to', None)
@@ -123,8 +123,6 @@ def calculate(cls, instance, **kwargs):
                     contract = instance.contract_details.contract
                 if instance.__class__.__name__ == "ContractDetails":
                     contract = instance.contract
-
-                
                 if contract:
                     validity_from = validity_from or contract.date_valid_from
                     validity_to = validity_to or contract.date_valid_to