code: def data_size(self, live_data=None):
          
          if live_data is not None:
              warnings.warn("The 'live_data' keyword argument is deprecated.",
                            DeprecationWarning)
          output = self.nodetool('info')[0]
          return _get_load_from_info_output(output)
docs: Uses `nodetool info` to get the size of a node's data in KB.