protected void handleFinishedChild(int currentChildIndex) throws Exception {
    children.get(currentChildIndex).close();
    children.set(currentChildIndex, null);
  }
@param currentChildIndex the index of the child
@throws Exception Potential Exception thrown by Operator.close()
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/execution/operator/process/AbstractConsumeAllOperator.java