text: 'use strict'
  
  module.exports = {
  
    XHTML_NAMESPACE: 'http://www.w3.org/1999/xhtml',
  
    $name: Symbol('name'),
    $nodeType: Symbol('nodeType'),
    $parent: Symbol('parent'),
    $settings: Symbol('settings'),
    $window: Symbol('window'),
  
    defineConstants: (object, constants) => {
      Object.keys(constants).forEach(name => {
        Object.defineProperty(object, name, {
          value: constants[name],
          writable: false
        })
      })
    }
  
  }
  