code: function tryAutoDetect(){
    var libs = [
        "es6-promise",
        "promise",
        "native-promise-only",
        "bluebird",
        "rsvp",
        "when",
        "q",
        "pinkie",
        "lie",
        "vow"]
    var i = 0, len = libs.length
    for(; i < len; i++){
      try {
        return loadImplementation(libs[i])
      } catch(e){}
    }
    return null
  }
docs: Look for common libs as last resort there is no guarantee that
  this will return a desired implementation or even be deterministic.
  The priority is also nearly arbitrary. We are only doing this
  for older versions of Node.js <0.12 that do not have a reasonable
  global.Promise implementation and we the user has not registered
  the preference. This preserves the behavior of any-promise <= 0.1
  and may be deprecated or removed in the future