code: function wrapWithLayout(page, drizzleData) {
    const layout = page.data.layout || drizzleData.options.layouts.page;
    // TODO Add test to see if _any_ extends is extant. Multiple extends
    // for ANY reason will cause handlebars-layouts to asplode.
    const alreadyWrapped = new RegExp(
      `{{\\s*#extend\\s*['"]${layout}['"].*}}`
    ).test(page.contents);
    const wrapped = alreadyWrapped
      ? page.contents
      : `  {{#extend '${layout}' }}
      {{#content 'main'}}${page.contents}{{/content}}
    {{/extend}}`;
    return wrapped;
  }
docs: Wrap the page's current contents with an `extend` helper
  so that it extends its layout. If no layout was set in frontmatter,
  a default will be used. Any hbs template can be used as the layout
  for a page as long as it contains a `#block` with the id of `body`.
  
  If the page's contents already contains an `{{#extend}}` helper invocation
  keyed to its layout (e.g. `{{#extend 'foo'}}` if the page's layout was set
  to `foo` in frontMatter, it will not double-wrap it. This is to prevent
  errors if a designer/developer creates a page file with the `{{#extend}}`
  already in it.
  
  @param {Object} page
  @param {Object} drizzleData
  @return {String} wrapped contents