func (b *Batcher) Load() interface{} {
    b.mu.Lock()
    defer b.mu.Unlock()

    if !b.first {
        b.con.Wait()

        if !b.second {
            b.con.Wait()
        }

        b.second = false

        b.value = b.valueSlow.Load()
        b.first = true
        b.con.Broadcast()
    }
    b.first = false

    b.mu.Unlock()

    b.value = b.valueSlow.Load()

    b.mu.Lock()

    b.second = true
    b.con.Broadcast()
    b.first = true
    return b.value
}