### Describe the enhancement requested Currently, we test spark with environment variable to get test data director: https://github.com/apache/incubator-graphar/blob/1bb04683f48ef9b0342d8378adc1deadc7318224/.github/workflows/spark.yaml#L44-L45 It will be more friendly for developers to test with default path of `testing` under project director ### Component(s) Java, Spark