function generateSampleRows(rowCount) {
  var rows = new Array(rowCount);

  for (var i = 0; i < rowCount; i++) {
    rows[i] = lf.Row.create({
      'id': 'id' + i.toString()
    });
  }

  return rows;
}
Generates sample data for testing.
@param {number} rowCount The number of sample rows to be generated.
@return {!Array<!lf.Row>}