code: def _build_entity_index(self, run_info, sampling_rate):
          ''' Build the entity index from run information. '''
  
          index = []
          interval = int(round(1000. / sampling_rate))
          _timestamps = []
          for run in run_info:
              reps = int(math.ceil(run.duration * sampling_rate))
              ent_vals = list(run.entities.values())
              df = pd.DataFrame([ent_vals] * reps, columns=list(run.entities.keys()))
              ts = pd.date_range(0, periods=len(df), freq='%sms' % interval)
              _timestamps.append(ts.to_series())
              index.append(df)
          self.timestamps = pd.concat(_timestamps, axis=0, sort=True)
          return pd.concat(index, axis=0, sort=True).reset_index(drop=Truef _build_entity_index(self, run_info, sampling_rate):
          ''' Build the entity index from run information. '''
  
          index = []
          interval = int(round(1000. / sampling_rate))
          _timestamps = []
          for run in run_info:
              reps = int(math.ceil(run.duration * sampling_rate))
              ent_vals = list(run.entities.values())
              df = pd.DataFrame([ent_vals] * reps, columns=list(run.entities.keys()))
              ts = pd.date_range(0, periods=len(df), freq='%sms' % interval)
              _timestamps.append(ts.to_series())
              index.append(df)
          self.timestamps = pd.concat(_timestamps, axis=0, sort=True)
          return pd.concat(index, axis=0, sort=True).reset_index(drop=True)
docs: Build the entity index from run information.