{
  "size1": 6,
  "size2": 7,
  "root1": "duZ9rbzfHhDht03cYIq9L5jfsW+851J3tSMqEn8gh+8=",
  "root2": "3bib5AOAnjJXUNPSY814kpwpQreUKjS3fhIslZSnTIw=",
  "proof": [],
  "desc": "empty proof",
  "wantErr": true
}