text: export default function compressBorder(node) {
      node.children.forEach((node, item, list) => {
          if (node.type === 'Identifier' && node.name.toLowerCase() === 'none') {
              if (list.head === list.tail) {
                  // replace `none` for zero when `none` is a single term
                  item.data = {
                      type: 'Number',
                      loc: node.loc,
                      value: '0'
                  };
              } else {
                  list.remove(item);
              }
          }
      });
  };
  