type BufCloser struct {
    *bytes.Buffer
}

func (bc BufCloser) Close() error {
    bc.Truncate(0)
    return nil
}

func BenchmarkGetBlockBodies(t *testing.B) {
    ctx := context.Background()
    var bts []byte
    r := BufCloser{
        Buffer: bytes.NewBuffer(bts),
    }
    byteString := []byte(strings.Repeat("A", 32))

    t.ResetTimer()
    for j := 0; j < t.N; j++ {
        t.StopTimer()
        for i := 0; i < 5; i++ {
            resp := network.GetBodyResponse{
                Data: byteString,
            }

            resp.Write(r)
        }

        t.StartTimer()
        blocksC, errC := GetBlockBodiesChan(ctx, r, 5)

        go func() {
            err := <-errC
            if err != nil {
                fmt.Println(err)
            }
        }()

        for item := range blocksC {
            fmt.Println(len(item))
        }
    }

}