def clear
      @mutex.synchronize do
        @values.clear
        @count.value = 0
        @next_scale_time.value = Time.now + RESCALE_THRESHOLD
        @start_time = Time.now
      end
    end
def clear
      @mutex.synchronize do
        @values.clear
        @count.value = 0
        @next_scale_time.value = Time.now + RESCALE_THRESHOLD
        @start_time = Time.now
      end
    end
1 hour