@include keyframes(swing) {
	20%, 40%, 60%, 80%, 100% {@include transform-origin(top center);}
	20% {@include transform(rotate(15deg));}
	40% {@include transform(rotate(-10deg));}
	60% {@include transform(rotate(5deg));}
	80% {@include transform(rotate(-5deg));}
	100% {@include transform(rotate(0deg));}
}

@mixin swing($count: $countDefault, $duration: $durationDefault, $delay: $delayDefault, $function: $functionDefault, $fill: $fillDefault, $visibility: $visibilityDefault) {
  @include transform-origin(top center);
  @include animation-name(swing);
  @include count($count);
  @include duration($duration);
  @include delay($delay);
  @include function($function);
  @include fill-mode($fill);
  @include visibility($visibility);
}