How to use the riot.unregister function in riot

tags.forEach(oneTag => {
    const rootName = oneTag.boundAs || guessRootName(oneTag);
    const { content } = oneTag || {};
    const code = content ? content.trim() : oneTag || '';
    const compiled = code.includes(alreadyCompiledMarker) ? code : compileText(code, rootName);
    unregister(rootName);
    eval(getRidOfRiotNoise(`${compiled}`)); // eslint-disable-line no-eval
  });
  const sourceCode = compiler.compile(`${template}`, {});

export default function renderMain({
  storyFn,
  selectedKind,
  selectedStory,
  showMain = () => {},
  showError = () => {},
}) {
  showMain();
  unregister('#root');
  const rootElement = document.getElementById('root');
  rootElement.innerHTML = '';
  rootElement.dataset.is = 'root';
  const element = storyFn();
  const rendered = renderRiot(element);
  if (!rendered) {
    showError({
      title: `Expecting a riot snippet or a riot component from the story: "${selectedStory}" of "${selectedKind}".`,
      description: dedent`
        Did you forget to return the component snippet from the story?
        Use "() => " or when defining the story.
      `,
    });
  }
  return rendered;
}