def METHOD_NAME(self):
    ctx = {
        "langpack-creator": "Mozilla.org",
        "langpack-contributors": "Joe Smith, Mary White",
    }
    os.environ["MOZ_BUILD_DATE"] = "20210928100000"
    manifest = langpack_manifest.create_webmanifest(
        "en-US",
        "57.0.1",
        "57.0",
        "57.0.*",
        "Firefox",
        "/var/vcs/l10n-central",
        "langpack-ca-valencia@firefox.mozilla.og",
        ctx,
        {},
    )
    data = json.loads(manifest)
    self.assertEqual(data["name"], "Language: English (US)")
    self.assertEqual(
        data["description"],
        "Firefox Language Pack for English (US) (en-US)",
    )