code: function removeColumn(opts: Options, change: Change, at: number): Change {
      const { value } = change;
      const { startKey } = value;
  
      const pos = TablePosition.create(opts, value.document, startKey);
  
      let columnKey;
      if (typeof at === 'undefined') {
          columnKey = pos.cell.key;
      } else {
          columnKey = pos.row.nodes.get(at).key;
      }
  
      return removeColumnByKey(opts, change, columnKey);
  }
docs: Delete current column in a table