{  "name": "grow_replace",  "kind": "diff",  "description": "replace two lines with three",  "a_hex": "700a710a",  "b_hex": "780a790a7a0a",  "edits": [    {      "op": "delete",      "a": 0,      "len": 2    },    {      "op": "insert",      "b": 0,      "len": 3    }  ],  "hunks": [    {      "base": [        0,        2      ],      "new": [        0,        3      ]    }  ]}