code: def synchronize_push(self, idx: Optional[int] = None) -> None:
      # Synchronize the push command of stream `idx` or all commands:
      if idx is None:
          for idx in range(self.pool_size):
              self.synchronize_push(idx)
          self._push_index = -1
      else:
          torch.cuda.synchronize(self._push_stream(idx))
          self._push_cache[idx] = None
  
imports: from typing import Optional, Callable
  import torch
  from torch import Tensor
  from torch.cuda import Stream
  from dig_ext.sync import synchronize, read_async, write_async
label_desc: Use image node_id 12 for calling the AsyncIOPool obj's underlying member method code with example usage: obj.synchronize_push(idx) without return types