code: function canonicalizeResource (resource) {
    var url = parse(resource, true)
      , path = url.pathname
      , buf = []
      ;
  
    Object.keys(url.query).forEach(function(key){
      if (!~keys.indexOf(key)) return
      var val = '' == url.query[key] ? '' : '=' + encodeURIComponent(url.query[key])
      buf.push(key + val)
    })
  
    return path + (buf.length ? '?' + buf.sort().join('&') : '')
  }
docs: Perform the following:
  
  - ignore non sub-resources
  - sort lexicographically
  
  @param {String} resource
  @return {String}
  @api private