old_contents: const FIRST_ROW = 0;
  const FIRST_COL = 0;
  
  const CHAR_CODE_OFFSET = 65;
  const LABEL_OFFSET = 1;
  
  const calculateLabel = function calculateLabel(row, col) {
    const rowLabel = String.fromCharCode(CHAR_CODE_OFFSET + row);
    const colLabel = col + LABEL_OFFSET;
  
    return colLabel + rowLabel;
  };
  
  const constAttr = function constAttr(obj, attr, value) {
    Reflect.defineProperty(obj, attr, {
      value,
      writable:   false,
      enumerable: true
    });
  };
  
  // Tile factory
  //
  // Takes 0-indexed row and col values
  const createTile = function createTile(row = FIRST_ROW, col = FIRST_COL) {
    const label = calculateLabel(row, col);
  
    const tile = {};
  
    constAttr(tile, 'row', row);
    constAttr(tile, 'col', col);
    constAttr(tile, 'label', label);
  
    return tile;
  };
  
  export default createTile;
  
new_contents: const FIRST_ROW = 0;
  const FIRST_COL = 0;
  
  const CHAR_CODE_OFFSET = 65;
  const LABEL_OFFSET = 1;
  
  const calculateLabel = function calculateLabel(row, col) {
    const rowLabel = String.fromCharCode(CHAR_CODE_OFFSET + row);
    const colLabel = col + LABEL_OFFSET;
  
    return colLabel + rowLabel;
  };
  
  const constAttr = function constAttr(obj, attr, value) {
    return Reflect.defineProperty(obj, attr, {
      value,
      writable:   false,
      enumerable: true
    });
  };
  
  // Tile factory
  //
  // Takes 0-indexed row and col values
  const createTile = function createTile(row = FIRST_ROW, col = FIRST_COL) {
    const label = calculateLabel(row, col);
  
    const tile = {};
  
    constAttr(tile, 'row', row);
    constAttr(tile, 'col', col);
    constAttr(tile, 'label', label);
  
    return tile;
  };
  
  export default createTile;
  
subject: Return the result of defineProperty