LilyPond Internals Reference: 2.2.87 Merge_mmrest_numbers_engraver

### 2.2.87 `Merge_mmrest_numbers_engraver`

Engraver to merge multi-measure rest numbers in multiple voices.

This works by gathering all multi-measure rest numbers at a time step. If they all have the same text and there are at least two only the first one is retained and the others are hidden.

`Merge_mmrest_numbers_engraver` is part of the following context(s) in `\layout`: `DrumStaff`, `GregorianTranscriptionStaff`, `InternalGregorianStaff`, `KievanStaff`, `MensuralStaff`, `PetrucciStaff`, `Staff`, `TabStaff` and `VaticanaStaff`.

#### LilyPond – Internals Reference v2.24.4 (stable-branch).