code: public List<RpcResponse> request(List<RpcRequest> reqList) {
          for (RpcRequest req : reqList) {
              this.reqList.add(req);
          }
  
          return null;
      }
docs: Adds all requests in reqList to internal request list
  
  @param reqList Requests to add to call batch
  @return Always returns null
  @throws IllegalStateException if batch has already been sent