code: function removeRow(opts: Options, change: Change, at: number): Change {
      const { value } = change;
      const { startKey } = value;
  
      const pos = TablePosition.create(opts, value.document, startKey);
  
      let rowKey;
      if (typeof at === 'undefined') {
          rowKey = pos.row.key;
      } else {
          rowKey = pos.table.nodes.get(at).key;
      }
  
      return removeRowByKey(opts, change, rowKey);
  }
docs: Remove current row in a table. Clear it if last remaining row