WIP: Decision listener test case fixed

Author: muzahidul-opti

Tests/OptimizelyTests-Common/DecisionListenerTests.swift

@@ -1262,6 +1262,16 @@ class FakeDecisionService: DefaultDecisionService {
         let featureDecision = FeatureDecision(experiment: experiment, variation: tmpVariation, source: source)
         return DecisionResponse.responseNoReasons(result: featureDecision)
     }
+    
+    override func getVariationForFeatureExperiment(config: ProjectConfig, featureFlag: FeatureFlag, user: OptimizelyUserContext, userProfileTracker: UserProfileTracker? = nil, options: [OptimizelyDecideOption]? = nil) -> DecisionResponse<FeatureDecision> {
+        guard let experiment = self.experiment, let tmpVariation = self.variation else {
+            return DecisionResponse.nilNoReasons()
+        }
+        
+        let featureDecision = FeatureDecision(experiment: experiment, variation: tmpVariation, source: source)
+        return DecisionResponse.responseNoReasons(result: featureDecision)
+    }
+    
 }
 
 fileprivate extension HandlerRegistryService {