code: def test_network_monitor():
      network_monitor = NetworkMonitor()
      network_monitor.collect_metrics()
  
      assert len(network_monitor.metrics.keys()) > 0
      assert isinstance(
          network_monitor.metrics["network_receive_megabytes"], float
      )
      assert isinstance(
          network_monitor.metrics["network_transmit_megabytes"], float
      )
  
      network_monitor.collect_metrics()
      aggregated_metrics = network_monitor.aggregate_metrics()
      assert len(aggregated_metrics.keys()) > 0
  
      assert isinstance(
          aggregated_metrics["network_receive_megabytes"], float
      )
      assert isinstance(
          aggregated_metrics["network_transmit_megabytes"], float
      )
  
      network_monitor.clear_metrics()
      assert len(network_monitor.metrics.keys()) == 0
  
imports: from mlflow.system_metrics.metrics.cpu_monitor import CPUMonitor
  from mlflow.system_metrics.metrics.disk_monitor import DiskMonitor
  from mlflow.system_metrics.metrics.gpu_monitor import GPUMonitor
  from mlflow.system_metrics.metrics.network_monitor import NetworkMonitor
label_desc: Use image node_id 4 for calling a global function with example usage: test_network_monitor() without return types