code: function documentWidth () {
    return Math.max(
      document.documentElement.clientWidth || 0,
      document.body.scrollWidth || 0,
      document.documentElement.scrollWidth || 0,
      document.body.offsetWidth || 0,
      document.documentElement.offsetWidth || 0)
  }
docs: documentWidth : documentWidth()
  Returns the width of the document.
  Compare with jQuery's `$(document).width()`.
  
  var documentWidth = require('dom101/document-width');
  
  var width = documentWidth();