json_schema: {
      "description": "An instance of <a href=\"#plugin-engine\">a plugin engine</a>.",
      "properties": {
          "manifest": {
              "description": "The manifest to read to know the configuration of the plugin.",
              "example": "manifest.json",
              "title": "Manifest",
              "type": "string"
          },
          "prefix": {
              "description": "The prefix of the url.",
              "example": "./other-plugin-folder/",
              "title": "Prefix",
              "type": "string"
          },
          "uid": {
              "description": "The UID of the engine.",
              "example": "com.awesome.plugin",
              "title": "UID",
              "type": "string"
          },
          "url": {
              "description": "The url/root of the Plugin relative to the prefix.",
              "example": "AwesomePlugin",
              "title": "URL",
              "type": "string"
          }
      },
      "required": [
          "uid"
      ],
      "title": "PluginEngineConfig",
      "type": "object"
  }