{
    "$schema": "http://json-schema.org/draft-04/schema#",
    "id": "#/definitions/preRequestScript",
    "oneOf": [
        {
            "type": "string"
        },
        {
            "type": "null"
        }
    ],
    "description": "In some use cases, it's necessary to run a bit of code or perform some tasks before sending a request. Postman implements this feature by the use of this field. Any code written to this field is run before running a request."
}