code: function extractFonts (state) {
    var list = String(state.list.buffer).split(',')
  
    var res = list.filter(function (font) {
      var extname = path.extname(font)
  
      return extname === '.woff' ||
        extname === '.woff2' ||
        extname === '.eot' ||
        extname === '.ttf'
    })
  
    return res
  }
docs: Specific to the document node's layout