@Override
    public String toString() {
        return StringFactory.storageString(null == Spark.getContext() ? "spark:none" : Spark.getContext().master());
    }
@param pattern
@return true if the pattern is actually a path as of the path definition in {@linkplain Storage}

NOTE: a more precise syntax check is possible
spark-gremlin/src/main/java/org/apache/tinkerpop/gremlin/spark/structure/io/SparkContextStorage.java