function generateTestData_() {
  let ss = SpreadsheetApp.getActiveSpreadsheet();
  let sheet = findResponseSheetForForm_(ss);
  if (!sheet) {
    let msg = 'No response sheet found. Create the form and try again.';
    SpreadsheetApp.getUi().alert(msg);
  }
  if (sheet.getLastRow() > 1) {
    let msg = 'Response sheet is not empty, can not generate test data. ' +
      'Remove responses and try again.';
    SpreadsheetApp.getUi().alert(msg);
    return;
  }

  let activities = loadActivitySchedule_(ss);
  let choices = fillArray_([], activities.length, '');
  range_(1, 5).forEach(function(value) {
    choices[value] = toOrdinal_(value);
  });

  let rows = range_(1, NUM_TEST_USERS).map(function(value) {
    let randomizedChoices = shuffleArray_(choices);
    let email = Utilities.formatString('person%d@example.com', value);
    return [new Date(), email].concat(randomizedChoices).concat(['Yes']);
  });
  bulkAppendRows_(sheet, rows);
}
Simulates a large number of users responding to the form. This enables users to quickly
experience the full solution without having to collect sufficient form responses
through other means.