resources/scss/bootstrap/mixins/_progress-bar.scss

   1 // Progress bars
   2
   3 @mixin progress-bar-variant($color) {
   4   background-color: $color;
   5
   6   // Deprecated parent class requirement as of v3.2.0
   7   .progress-striped & {
   8         @include gradient-striped;
   9   }
  10 }