code: def __init__(self, in_dim, out_dim):
      super().__init__()
      self.q_net = nn.Linear(in_dim, out_dim)
      self.k_net = nn.Linear(in_dim, out_dim)
      self.v_net = nn.Linear(in_dim, out_dim)
  
file_path: qlib/qlib/rl/order_execution/network.py
imports: from __future__ import annotations
  from typing import List, Tuple, cast
  import torch
  import torch.nn
  from tianshou.data import Batch
  from qlib.typehint import Literal
  from .interpreter import FullHistoryObs
label_desc: Use image node_id 1 to create a new Attention object from inherited base classes: nn with example: obj = Attention(in_dim, out_dim)