Repeated keystroke "w" for Agar.io I've been searching for the relevant articles on the Internet and found nothing useful. Maybe I'm too stupid to understand.

I would like to create a script that automatically keep pressing the "W" key, like wwwwwwwwwwwwwwwwwwwwwwwwwww, endlessly and as quick as possible when I press and hold the key, and it ends when I release the key. 

"defaults write -g ApplePressAndHoldEnabled -bool false" doesn't work in this case.

Thank you very much in advanced.
Karabiner:

  &lt;item&gt;
    &lt;identifier&gt;private.w2wRepeat&lt;/identifier&gt;
    &lt;name&gt;Turn W key to W key repeat&lt;/name&gt;
    &lt;autogen&gt;
      __KeyToKey__
      KeyCode::W,
      KeyCode::W,
      DelayUntilRepeat::RawValue::1,
      KeyRepeat::RawValue::1,
    &lt;/autogen&gt;
  &lt;/item&gt;