Error

import 'package:bloc_pattern/bloc_pattern.dart';
import 'package:flutter/material.dart';
import 'package:fluttetube/blocs/videos_bloc.dart';
import 'package:fluttetube/screens/home_screen.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return BlocProvider(
    // isso aqui ta certo? no video ta diferente...
        blocs: [Bloc((i) => VideosBloc())],
        child: MaterialApp(
          debugShowCheckedModeBanner: false,
          title: 'Flutter Demo',
          theme: ThemeData(
            primarySwatch: Colors.blue,
          ),
          home: Home(),
        ));
  }
}

Main
------------------------------

// isso aqui é outro arquivo
import 'dart:async';

import 'package:bloc_pattern/bloc_pattern.dart';
import 'package:fluttetube/models/video_model.dart';
import 'package:fluttetube/services/api.dart';

class VideosBloc extends BlocBase {
  Api api;
  List<Video> videos;

  // expondo a stream--- ta saindo o video
  final _videosController = StreamController<List<Video>>();

  Stream get outVideos => _videosController.stream;

  //------------------------------------------
  final _searchController = StreamController<String>();

  // expondo o sink --- ta entrando uma pesquisa
  Sink get inSearch => _searchController.sink;

  VideosBloc() {
    api = Api();
    //toda entrada ele pesquisa
    _searchController.stream.listen(_search);
  }

  void _search(String search) async {
    print(search);
    videos = await api.search(search);
  }

  @override
  void dispose() {
    super.dispose();
    _videosController.close();
    _searchController.close();
  }
}