code: def testCopySHMtoDefault(self):
      s = shared_memory.SharedMemory(
          name="test_X", create=True, size=N * N * 4
      )
      s.close()
      if CI and not OSX:
          t = Tensor.empty(
              N, N, device="disk:/dev/shm/test_X"
          ).realize()
      else:
          t = Tensor.empty(N, N, device="disk:shm:test_X").realize()
      for _ in range(3):
          with Timing(
              "sync:  ",
              on_exit=lambda ns: f" @ {t.nbytes()/ns:.2f} GB/s",
          ):
              with Timing("queue: "):
                  t.to(Device.DEFAULT).realize()
              Device[Device.DEFAULT].synchronize()
      s.unlink()
  
file_path: tinygrad/test/test_copy_speed.py
imports: import unittest
  from tinygrad import Tensor
  from tinygrad import Device
  from tinygrad.helpers import Timing, CI, OSX
  import multiprocessing.shared_memory
label_desc: Use image node_id 2 for calling the TestCopySpeed obj's underlying member method code with example usage: obj.testCopySHMtoDefault() without return types