message: fix: update breadcrumb
diff: /** @jsx jsx */
  import { jsx } from "@emotion/core";
  -import { Children, cloneElement, forwardRef } from "react";
  +import { cloneElement, forwardRef } from "react";
  import Box from "../Box";
  import Link from "../Link";
  import { cleanChildren } from "../utils";
  @@ -68,12 +68,12 @@ const Breadcrumb = ({
  ...rest
  }) => {
  const validChildren = cleanChildren(children);
  - const clones = validChildren((child, index) => {
  + const clones = validChildren.map((child, index) => {
  return cloneElement(child, {
  addSeparator,
  separator,
  spacing,
  - isLastChild: Children.count(children) === index + 1,
  + isLastChild: validChildren.length === index + 1,
  });
  });
  