function extractLabel(label) {
  if (typeof label !== 'string' || !LABEL_EXTRACT_REGEXP.test(label)) {
    return [];
  }

  var _label$toUpperCase$ma = label.toUpperCase().match(LABEL_EXTRACT_REGEXP),
      columnAbs = _label$toUpperCase$ma[1],
      column = _label$toUpperCase$ma[2],
      rowAbs = _label$toUpperCase$ma[3],
      row = _label$toUpperCase$ma[4];

  return [{
    index: rowLabelToIndex(row),
    label: row,
    isAbsolute: rowAbs === '$'
  }, {
    index: columnLabelToIndex(column),
    label: column,
    isAbsolute: columnAbs === '$'
  }];
}
Extract cell coordinates.

@param {String} label Cell coordinates (eq. 'A1', '$B6', '$N$98').
@returns {Array} Returns an array of objects.