libvirt/tests/qemublocktestdata/xml2json/file-vhd-noopts.json

{
  "node-name": "test1",
  "read-only": false,
  "driver": "vhdx",
  "file": "test2"
}
{
  "driver": "file",
  "filename": "/path/to/i.img",
  "node-name": "test2",
  "read-only": false,
  "discard": "unmap"
}