chromium/extensions/test/data/manifest_tests/sandbox_dictionary_2.json

{
  "name": "test",
  "version": "0.1",
  "manifest_version": 3,
  "sandbox": {
    "pages": ["test"]
  },
  "content_security_policy" : {
    "extension_pages" : "script-src; object-src;"
  }
}