code: def forward(self):
      relative_position_bias = self.relative_position_bias_table[
          self.relative_position_index.view(-1)
      ].view(
          self.window_size[0] * self.window_size[1] + 1,
          self.window_size[0] * self.window_size[1] + 1,
          -1,
      )  # Wh*Ww,Wh*Ww,nH
      return relative_position_bias.permute(2, 0, 1).contiguous()
  
imports: import math
  from functools import partial
  import torch
  import torch.nn
  import torch.nn.functional
  import torch.utils.checkpoint
  from timm.models.layers import drop_path, to_2tuple, trunc_normal_
  from timm.models.registry import register_model
  from lavis.common.dist_utils import download_cached_file
label_desc: Use image node_id 2 for calling the RelativePositionBias obj's underlying member method code with example usage: obj.forward() and returns: relative_position_bias