@VisibleForTesting
  static ImageMetadataOutput fromJson(String json) throws IOException {
    return JsonTemplateMapper.readJson(json, ImageMetadataOutput.class);
  }
Builds a JSON string containing metadata about a {@link JibContainer} from a build.

<p>Example:

<pre>{@code
{
  "image": "gcr.io/project/image:tag",
  "imageId": "sha256:61bb3ec31a47cb730eb58a38bbfa813761a51dca69d10e39c24c3d00a7b2c7a9",
  "imageDigest": "sha256:3f1be7e19129edb202c071a659a4db35280ab2bb1a16f223bfd5d1948657b6f",
  "tags": ["latest", "tag"]
}
}</pre>
jib-plugins-common/src/main/java/com/google/cloud/tools/jib/plugins/common/ImageMetadataOutput.java