public function storeOutcomeVariable(RunnerServiceContext $context, $itemUri, $variableIdentifier, $variableValue)
    {
        $this->assertQtiRunnerServiceContext($context);
        $metaVariable = $this->getOutcomeVariable($variableIdentifier, $variableValue);
        return $this->storeVariable($context, $itemUri, $metaVariable);
    }