code: func (t *SleeperChaincode) query(stub shim.ChaincodeStubInterface, args []string) pb.Response {
  	key := args[0]
  
  	// Get the state from the ledger
  	val, err := stub.GetState(key)
  	if err != nil {
  		return shim.Error(err.Error())
  	}
  
  	sleepTime := args[1]
  
  	//sleep for a bit
  	t.sleep(sleepTime)
  
  	return shim.Success(val)
  }
docs: // query callback representing the query of a chaincode