AdminLTE/scss/dark/bootstrap/utilities/_api.scss

// Loop over each breakpoint
@each $breakpoint in map-keys($grid-breakpoints) {

  // Generate media query if needed
  @include media-breakpoint-up($breakpoint) {
    $infix: breakpoint-infix($breakpoint, $grid-breakpoints);

    // Loop over each utility property
    @each $key, $utility in $utilities-alt {
      // The utility can be disabled with `false`, thus check if the utility is a map first
      // Only proceed if responsive media queries are enabled or if it's the base media query
      @if type-of($utility) == "map" and (map-get($utility, responsive) or $infix == "") {
        @include generate-utility($utility, $infix);
      }
    }
  }
}