code: def test_get_cpu_memory_from_gc():
      old_mem = get_cpu_memory_from_gc()
      _ = torch.randn(10, 128)
      new_mem = get_cpu_memory_from_gc()
      assert new_mem - old_mem == 10 * 128 * 4
  
file_path: pytorch_geometric/test/profile/test_profile_utils.py
imports: import torch
  from torch.nn import Linear
  from torch_geometric.data import Data
  from torch_geometric.profile import count_parameters, get_cpu_memory_from_gc, get_data_size, get_gpu_memory_from_gc, get_gpu_memory_from_ipex, get_gpu_memory_from_nvidia_smi, get_model_size
  from torch_geometric.profile.utils import byte_to_megabyte, medibyte_to_megabyte
  from torch_geometric.testing import onlyCUDA, onlyXPU, withPackage
  from torch_geometric.typing import SparseTensor
label_desc: Use image node_id 5 for calling a global function with example usage: test_get_cpu_memory_from_gc() without return types