code: def read_value(self):
          
          pass
          # Kick off a query to read the value of the descriptor, then wait
          # for the result to return asyncronously.
          self._value_read.clear()
          self._device._peripheral.readValueForDescriptor(self._descriptor)
          if not self._value_read.wait(timeout_sec):
              raise RuntimeError('Exceeded timeout waiting to read characteristic value!')
          return self._value
docs: Read the value of this descriptor.