@AssertTrue(message = "Use a valid storage level option. See org.apache.spark.storage.StorageLevel")
	public boolean isSparkStorageValid() {
		if (storageLevel.length() == 0) {
			return true;
		}
		else {
			try {
				StorageLevel.fromString(storageLevel);
				return true;
			}
			catch (IllegalArgumentException e) {
				return false;
			}
		}
	}
Default module options for {@link org.springframework.xd.spark.streaming.SparkStreamingSupport}.
Both the java and scala based implementations can extend this.

@author Ilayaperumal Gopinathan
spring-xd-spark-streaming/src/main/java/org/springframework/xd/spark/streaming/DefaultSparkStreamingModuleOptionsMetadata.java