code: def _mergeKerningDictionaries(kerningDictionaries):
      
      # work through the dictionaries backwards since
      # this uses an update to load the kerning. this
      # will ensure that the script order is honored.
      kerning = {}
      for dictionaryGroup in reversed(kerningDictionaries):
          for dictionary in dictionaryGroup:
              kerning.update(dictionary)
      # done.
      return kerning
docs: Merge all of the kerning dictionaries found into
      one flat dictionary.