code: def flush_gradients(self):
      self._flush_gradient_swapper(self.gradient_swapper)
  
imports: import torch
  from deepspeed.utils.logging import logger
  from deepspeed.ops.op_builder import AsyncIOBuilder
  from deepspeed import comm
  from deepspeed.runtime.swap_tensor.constants import *
  from deepspeed.runtime.swap_tensor.utils import swap_in_tensors, swap_out_tensors, print_object, get_sized_buffers
  from deepspeed.runtime.swap_tensor.async_swapper import AsyncTensorSwapper
  from deepspeed.runtime.swap_tensor.optimizer_utils import OptimizerSwapper
  from deepspeed.accelerator import get_accelerator
label_desc: Use image node_id 4 for calling the PartitionedOptimizerSwapper obj's underlying member method code with example usage: obj.flush_gradients() without return types