code: def testCopyCPUtoDefaultFresh(self):
      print("fresh copy")
      for _ in range(3):
          t = Tensor.rand(N, N, device="cpu").realize()
          with Timing(
              "sync:  ",
              on_exit=lambda ns: f" @ {t.nbytes()/ns:.2f} GB/s",
          ):  # noqa: F821
              with Timing("queue: "):
                  t.to(Device.DEFAULT).realize()
              Device[Device.DEFAULT].synchronize()
          del t
  
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 4 for calling the TestCopySpeed obj's underlying member method code with example usage: obj.testCopyCPUtoDefaultFresh() without return types