@Override
    public Feign internalBuild() {
      if (!(this.contract instanceof ReactiveDelegatingContract)) {
        super.contract(new ReactiveDelegatingContract(this.contract));
      } else {
        super.contract(this.contract);
      }
      return super.internalBuild();
    }
Build the Feign instance.

@return a new Feign Instance.
reactive/src/main/java/feign/reactive/ReactiveFeign.java