protected void complete() {
        this.memoryComputeKeys.values().stream().filter(MemoryComputeKey::isTransient).forEach(memoryComputeKey -> this.sparkMemory.remove(memoryComputeKey.getKey()));
    }
@author Marko A. Rodriguez (http://markorodriguez.com)
spark-gremlin/src/main/java/org/apache/tinkerpop/gremlin/spark/process/computer/SparkMemory.java