Confusing behavior regarding start position 0

I'm currently using the following "tail" configuration

```
Files
.tailLines(file)
.blocking()
.startPosition(startPosition)
.backpressureStrategy(BackpressureStrategy.BUFFER)
.build());
```

Where `startPosition` is either 0 or the length of the file. The problem I'm having is with `startingPosition=0`. I'd expect the `Flowable` to immediately begin emitting lines from the beginning of the file up into its end, and then start a "real" tail.

What instead happens is that as soon as the file changes (for example, lines are appended), lines from the beginning are emitted.

Isn't this a bit counterintuitive? If the file changes, I'd expect events that reflect this change, not lines from the beginning of the file.