class_docstr: Concurrent event loop context.
  
  Args:
      concurrency: max processing concurrency.
code: def start_loop(self):
      if not self._runner_t.is_alive():
          self._runner_t.start()
  
file_path: pytorch_geometric/torch_geometric/distributed/event_loop.py
imports: import asyncio
  import atexit
  import logging
  from threading import BoundedSemaphore, Thread
  from typing import Callable, Optional
  import torch
label_desc: Use image node_id 2 for calling the ConcurrentEventLoop obj's underlying member method code with example usage: obj.start_loop() without return types