{
    "tgt_signed_image": {
        "build": {
            "build_target": {
                "name": "grunt"
            },
            "version": "12499.42.0",
            "bucket": "chromeos-releases",
            "channel": "dev-channel"
        },
        "image_type": 6,
        "key": "mp-v5"
    },

    "src_signed_image": {
        "build": {
            "build_target": {
                "name": "grunt"
            },
            "version": "11021.17.0",
            "bucket": "chromeos-releases",
            "channel": "dev-channel"
        },
        "image_type": 6,
        "key": "premp-v4"
    },

    "bucket": "chromeos-releases-test",
    "verify": true,
    "keyset": "update_signer",
    "dryrun": false
  }