code: function propagateToGlobal (window) {
      for (var key in window) {
        if (!window.hasOwnProperty(key)) continue
        if (~blacklist.indexOf(key)) continue
        if (global[key]) {
          if (process.env.JSDOM_VERBOSE) {
            console.warn(
              "[jsdom] Warning: skipping cleanup of global['" + key + "']"
            )
          }
          continue
        }
  
        keys.push(key)
        global[key] = window[key]
      }
    }
docs: /*
  propagate keys from `window` to `global`