json_schema: {
      "$schema": "http://json-schema.org/draft-04/schema#",
      "title": "Investment Transaction",
      "type": "object",
      "additionalProperties": false,
      "properties": {
          "_id": {
              "type": "integer",
              "description": "A unique ID for InvestmentTransaction"
          },
          "price": {
              "type": "number"
          },
          "quantity": {
              "type": "number"
          }
      }
  }