code: def makeGlyphClassDefinitions(groups, feaFile=None, stripPrefix=""):
      
      classDefs = {}
      if feaFile is not None:
          classNames = {cdef.name for cdef in iterClassDefinitions(feaFile)}
      else:
          classNames = set()
      lengthPrefix = len(stripPrefix)
      for groupName, members in sorted(groups.items()):
          originalGroupName = groupName
          if stripPrefix and groupName.startswith(stripPrefix):
              groupName = groupName[lengthPrefix:]
          className = makeFeaClassName(groupName, classNames)
          classNames.add(className)
          classDef = makeGlyphClassDefinition(className, members)
          classDefs[originalGroupName] = classDef
      return classDefs
docs: Given a groups dictionary ({str: list[str]}), create feaLib
      GlyphClassDefinition objects for each group.
      Return a dict keyed by the original group name.
  
      If `stripPrefix` (str) is provided and a group name starts with it,
      the string will be stripped from the beginning of the class name.