/**
 * Return the unit context if has been set by the [s-unit-context mixin](../mixins/_s-unit-context.scss)
 *
 * @return 		{String} 				The unit context setted
 * @author 		Olivier Bossel <olivier.bossel@gmail.com> (https://olivierbossel.com)
 */
@function s-unit-context() {
  @if not $_s-unit-context {
    $_s-unit-context: s-setting("unit") !global;
  }
  @return $_s-unit-context;
}