message: `separate-draft-pr-button`: Fix console error in Private repos on free accounts
diff: @@ -2,7 +2,7 @@ import React from 'dom-chef';
  import select from 'select-dom';
  import features from '../libs/features';
  -function init(): void {
  +function init(): void | false {
  const previewForm = select('.new-pr-form');
  // PRs can't be created from some comparison pages:
  @@ -12,7 +12,12 @@ function init(): void {
  }
  const buttonBar = select('.timeline-comment > :last-child', previewForm)!;
  - const createPrButtonGroup = select('.BtnGroup', buttonBar)!;
  + const createPrButtonGroup = select('.BtnGroup', buttonBar);
  + if (!createPrButtonGroup) {
  + // Free accounts can't open Draft PRs in private repos, so this element is missing
  + return false;
  + }
  +
  const createPrDropdownItems = select.all('.select-menu-item', createPrButtonGroup);
  for (const dropdownItem of createPrDropdownItems) {
  