just something to test

Public/sass/bootstrap/mixins/_responsive-visibility.scss

@@ -0,0 +1,21 @@
+// Responsive utilities
+
+//
+// More easily include all the states for responsive-utilities.less.
+// [converter] $parent hack
+@mixin responsive-visibility($parent) {
+  #{$parent} {
+    display: block !important;
+  }
+  table#{$parent}  { display: table !important; }
+  tr#{$parent}     { display: table-row !important; }
+  th#{$parent},
+  td#{$parent}     { display: table-cell !important; }
+}
+
+// [converter] $parent hack
+@mixin responsive-invisibility($parent) {
+  #{$parent} {
+    display: none !important;
+  }
+}