public long getEstimatedMemoryUsageInBytes() {
    return calculateEstimatedRunningMemorySize() + calculateRetainedMemorySize();
  }
Get the memory usage in bytes of this pipeline. This method takes into account the memory usage
of the children pipelines. EstimatedSize = RunningMemorySize + RetainedMemorySize

@return memory usage in bytes.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/planner/memory/PipelineMemoryEstimator.java