Cannnot select default option in select input

[cyrus07424]

In @b4.select, '_default options always appear as disabled="disabled". So I cannot select default option.
I want to select empty value as default.
https://github.com/adrianhurt/play-bootstrap/blob/develop/play26-bootstrap4/module/app/views/b4/selectWithContent.scala.html

In "With default and Pears as value" of this example, It looks selectable default value.
https://adrianhurt.github.io/play-bootstrap/1.6-P28-B4/docs/#helper-select

But, when i run this sample, I also couldn't select default value.
https://github.com/adrianhurt/play-bootstrap/tree/develop/play26-bootstrap4/sample

is it specification? or problem?

[cyrus07424]

I think '_default argument should not be disabled. I prefer "disabled" attribute is optional.
#82