docs: def disambiguate(self, symclasses):
          """Use the connection to the atoms around a given vertex
          as a multiplication function to disambiguate a vertex"""
          offsets = self.offsets
          result = symclasses[:]
  	for index in self.range:
  	    try:
  		val = 1
  		for offset, bondtype in offsets[index]:
  		    val *= symclasses[offset] * bondtype
  	    except OverflowError:
                  # Hmm, how often does this occur?
  		val = 1L
  		for offset, bondtype in offsets[index]:
  		    val *= symclasses[offset] * bondtype
              result[index] = val
  	return result