the progress bar length is always changing when the idea console output.

4798 / 36850 [=====>---------------------------------------] 13.02 % 1506/s 21s

17718 / 36850 [========================================>--------------------------------------------] 48.08 % 2040/s 9s

this length is always changing.

```scala
val a=Array(1,2,3,4,5,6,7,8,9,10)
var pb = new ProgressBar(a.length)
//pb.showSpeed = true//默认true
for (_ <- 1 to a.length) {
pb.add(1)
Thread.sleep(1500)
}
println("done")
```

```xml

jitpack.io
https://jitpack.io


com.github.matfax
pb-scala
v0.3.2

```
```

The issue shows a progress bar whose length changes during output. Look at the ProgressBar class in the repository to understand how the bar is rendered. Check the logic for calculating bar length and updating the display. Run the provided Scala snippet to reproduce the issue, then modify the rendering to keep the bar length stable.

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