text: // @flow
  
  // generates uuid as per version 4 of RFC4122
  export function uuid() {
    return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
      var r = (Math.random() * 16) | 0,
        v = c == 'x' ? r : (r & 0x3) | 0x8
      return v.toString(16)
    })
  }
  