docs: def GrowInstanceDisk(r, instance, disk, amount, wait_for_sync=False):
      """
      Grows a disk of an instance.
  
      More details for parameters can be found in the RAPI documentation.
  
      @type instance: string
      @param instance: Instance name
      @type disk: integer
      @param disk: Disk index
      @type amount: integer
      @param amount: Grow disk by this amount (MiB)
      @type wait_for_sync: bool
      @param wait_for_sync: Wait for disk to synchronize
      @rtype: int
      @return: job id
      """
  
      body = {
          "amount": amount,
          "wait_for_sync": wait_for_sync,
      }
  
      return r.request("post", "/2/instances/%s/disk/%s/grow" %
                               (instance, disk), content=body)