How to set multiplier in layout constraints

[eugenesvk]

If I want to have a button twice the width of anothe button, I thought that it's what the multiplier field is for in the layout constraints
But then there is no api for setting it, and when I tried to monkey-patch-set it like the offset does it it had no effect since, as far as I understood it, the multiplier isn't actually used anywhere in setting up layouts?