Function
innermostOf
Common
```kotlin
fun RectRulers.Companion.innermostOf(vararg rulers: RectRulers): RectRulers
```
Merges multiple `RectRulers` into a single `RectRulers`, using the inner-most value. That is, the
`RectRulers.left` will be the greatest `RectRulers.left`, the `RectRulers.top` will be the
greatest `RectRulers.top`, the `RectRulers.right` will be the least `RectRulers.right`, and the
`RectRulers.bottom` will be the least of all `rulers`.
When `rulers` provide non-overlapping values, the result may have negative size. For example, if
one `RectRulers` provides (10, 20, 30, 40) as their ruler values, and another provides (1, 1, 5,
5), the merged result will be (10, 20, 5, 5).
If one of the `rulers` does not provide a value, it will not be considered in the calculation.