code: def flush_gradients(self):
      self._flush_gradient_swapper(self.gradient_swapper)
  
imports: from deepspeed.ops.aio 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
  from deepspeed.runtime.swap_tensor.async_swapper import AsyncTensorSwapper
  from deepspeed.runtime.swap_tensor.utils import get_sized_buffer
  from deepspeed.runtime.swap_tensor.optimizer_utils import OptimizerSwapper
label_desc: Use image node_id 4 for calling the PipelinedOptimizerSwapper obj's underlying member method code with example usage: obj.flush_gradients() without return types