{
  "protocol_feature_type": "builtin",
  "dependencies": [],
  "description_digest": "e5d7992006e628a38c5e6c28dd55ff5e57ea682079bf41fef9b3cced0f46b491",
  "subjective_restrictions": {
    "earliest_allowed_activation_time": "1970-01-01T00:00:00.000",
    "preactivation_required": true,
    "enabled": true
  },
  "builtin_feature_codename": "GET_BLOCK_NUM"
}