code: @Override
      public FeatureState getFeatureState(final Feature feature) {
          final Optional<FeatureState> featureState = findOne(feature.name());
          return featureState.orElse(null);
  
      }
docs: Get the persisted state of a feature from the repository. If the repository doesn't contain any information regarding
  this feature it must return <code>null</code>.
  
  @param feature The feature to read the state for
  @return The persisted feature state or <code>null</code>