[3.0.0-alpha.2] validate method callback is called twice or more(?)

[sqal]

vue & vue-validator version

vue@2.1.8, vue-validator@3.0.0-alpha.2

Reproduction Link

https://jsfiddle.net/sqal/21jse27u/

Steps to reproduce

1. Open reproduction link
2. Type something in input field
3. In console you should see that it logs validate callback twice every time you enter a value into input field

I am guessing it's called twice because I use two validators in my example?. But still is this correct behaviour? I can't remember this callback being called multiple times in vue-validator 2.x, So just want to make sure whether or not this is a bug or by design. Thanks :)

[kazuya kawaguchi]

Thank you for your feedback.

yes, validate method have some issues.
I'll improvement validate method.