async enhance (enhancers) {
    return Promise.all(
      enhancers.map(
        async ({ value: enhancer, name: pluginName }) => {
          try {
            await enhancer(this)
          } catch (error) {
            console.log(error)
            throw new Error(`[${pluginName}] execute extendPageData failed.`)
          }
        }
      )
    )
  }
Execute the page enhancers. A enhancer could do following things:

  1. Modify page's frontmatter.
  2. Add extra field to the page.

@api private