const graph = await walk(
      path.join(__dirname, 'examples/base/entry.js'),
      () => {}
);
console.log(graph);
/*
[
  {
    "filePath": "./test/examples/base/entry.js",
    "dependencies": [
      "./test/examples/base/a.js",
      "./test/examples/base/b.js",
    ],
  },
  {
    "filePath": "./test/examples/base/a.js",
    "dependencies": [
      "./test/examples/base/b.js",
      "./test/examples/base/c.js",
      "./test/examples/base/d.js",
    ],
  }
  ...
]
 */