code: def forward_only(self) -> torch.Tensor:
      return self._module(self._input_tensor, self._key, self._value)[0]
  
imports: from enum import Enum
  from typing import Callable, Dict, Optional, Tuple, Type, Union
  import torch
  import torch.nn
  import torch.nn.functional
  from opacus.grad_sample import GradSampleModule
  from opacus.grad_sample.utils import wrap_model
  from opacus.layers import DPGRU, DPLSTM, DPRNN, DPMultiheadAttention
  from opacus.layers.dp_rnn import DPRNNBase
label_desc: Use image node_id 3 for calling the MHABase obj's underlying member method code with example usage: obj.forward_only() and returns: self