anchor.diff:            "type": "object",
             "properties": {
               "submission_tos": { "type": "string" }
  -          }
  +          },
  +          "required": ["submission_tos"]
           },
           "payload_placement": {
             "enum": [
  
positive.code:               "minItems": 1,
                "uniqueItems": true
              }
            }
          },
          "keys": {
            "type": "array",
  
negative.code:           "properties": {
              "submitter": { "type": "string" },
              "signer": { "type": "string" },
              "submitter_type": {
                "enum": [
                  "anonymous",
                  "user",
                  "agent"
                ]
              }
            },
            "required": ["submitter_type"]
          }
        },
        "required": ["payload_placement"]
      }
    },
  
  