code: def value(self, index):
          "Gets a value from a given index."
          offset = units.offset(self._units[index])
          value_index = (index ^ offset) & units.PRECISION_MASK
          return units.value(self._units[value_index]f value(self, index):
          "Gets a value from a given index."
          offset = units.offset(self._units[index])
          value_index = (index ^ offset) & units.PRECISION_MASK
          return units.value(self._units[value_index])
docs: Gets a value from a given index.