https://github.com/mozilla/pdf.js/blob/0df1a5661958df0c4ed2f73b0f3266d825c5c280/src/display/api.js#L710-L719
The return type signature `@returns {Promise<{num: number, gen: number}>}` is mismatched with its definition. (should be `@returns {Promise<number>}`)
},
        reason => {
          intentState.streamReader = null;
          if (this._transport.destroyed) {
            return; 
          }
          if (intentState.operatorList) {
            
            intentState.operatorList.lastChunk = true;
            for (const internalRenderTask of intentState.renderTasks) {
              internalRenderTask.operatorListChanged();
            }
            this._tryCleanup();
          }
          if (intentState.displayReadyCapability) {
            intentState.displayReadyCapability.reject(reason);
          } else if (intentState.opListReadCapability) {
            intentState.opListReadCapability.reject(reason);
          } else {
            throw reason;
          }
        }
      );
    };
    pump();
  }
  /**
   * @private
   */
  _abortOperatorList({ intentState, reason, force = false }) {