code: def allEqualTo(ref, lst, mapper=None):
      if mapper is None:
          return all(ref == item for item in lst)
  
      mapped = mapper(ref)
      return all(mapped == mapper(item) for item in lst)
  
imports: from fontTools.misc.roundTools import noRound
  from .errors import VariationModelError
label_desc: Use image node_id 3 for calling a global function with example usage: allEqualTo(ref, lst, mapper) and returns: all, all