[or_am_i]

In JetBrains editors it's possible to highlight mutable variables, at least in the languages where the distinction exists. My go to setting in Kotlin is to underscore all `var`'s, for two reasons:

- this makes them really stand out, much easier to track the mutation visually,

- the underscore effect is intrusive just-enough to nudge you to think twice when adding a new `var`.

Nothing like diving into a >3k lines PR peppered with underscores.