code: function getCellData(column, rowData, rowNumber, tableData, columns, isBottomData) {
    var value = column.value;
    var id = column.id;
  
    // if it is bottom data, just use the value directly.
  
    if (isBottomData) {
      return rowData[id];
    }
  
    // call value as a function
    if (typeof value === 'function') {
      return value(rowData, { rowNumber: rowNumber, tableData: tableData, columns: columns });
  
      // interpret value as a key
    } else if (value != null) {
      return rowData[value];
    }
  
    // otherwise, use the ID as a key
    return rowData[id];
  }
docs: Gets the value of a cell given the row data. If column.value is
  a function, it gets called, otherwise it is interpreted as a
  key to rowData. If column.value is not defined, column.id is
  used as a key to rowData.
  
  @param {Object} column The column definition
  @param {Object} rowData The data for the row
  @param {Number} rowNumber The number of the row
  @param {Object[]} tableData The array of data for the whole table
  @param {Object[]} columns The column definitions for the whole table
  @return {Any} The value for this cell