code: function createPrefixedRule(rule, prefix) {
    const prefixLength = prefix.length;
    const selectorStart = rule.selector.slice(1, prefixLength + 1);
    const isAlreadyPrefixed = selectorStart === prefix;
    if (isAlreadyPrefixed) return false;
  
    return rule.clone({
      selector: `.${prefix + rule.selector.substring(1)}`,
    });
  }
docs: Creates a PostCSS rule based on breakpoint options
  @param {Object} rule PostCSS rule to duplicate
  @param {Object} prefix Prefix for selector
  @return {Object} Responsified PostCSS rule