The mask of a named scale, rejecting an unknown name.
Every public entry point that takes a scale name funnels through here, so a
typo is reported the same way everywhere instead of being answered with an
empty result that also means "this scale has none".
The mask of a named scale, rejecting an unknown name.
Every public entry point that takes a scale name funnels through here, so a typo is reported the same way everywhere instead of being answered with an empty result that also means "this scale has none".