code: def peak_memory_mb() -> float:
      
      if resource is None or sys.platform not in ('linux', 'darwin'):
          return 0.0
  
      # TODO(joelgrus): For whatever, our pinned version 0.521 of mypy does not like
      # next line, but later versions (e.g. 0.530) are fine with it. Once we get that
      # figured out, remove the type: ignore.
      peak = resource.getrusage(resource.RUSAGE_SELF).ru_maxrss  # type: ignore
  
      if sys.platform == 'darwin':
          # On OSX the result is in bytes.
          return peak / 1_000_000
  
      else:
          # On Linux the result is in kilobytes.
          return peak / 1_000
docs: Get peak memory usage for this process, as measured by
      max-resident-set size:
  
      https://unix.stackexchange.com/questions/30940/getrusage-system-call-what-is-maximum-resident-set-size
  
      Only works on OSX and Linux, returns 0.0 otherwise.