code: public FeatureManager build() {
          Validate.notBlank(name, "No name specified");
          Validate.notNull(featureProvider, "No feature provider specified");
          Validate.notNull(stateRepository, "No state repository specified");
          Validate.notNull(userProvider, "No user provider specified");
          Validate.notNull(strategyProvider, "No activation strategy provider specified");
          return new DefaultFeatureManager(name, featureProvider, stateRepository, userProvider, strategyProvider);
      }
docs: Create the {@link FeatureManager} using the current configuration of the builder