code: def forward(self, batch, key=None):
      if key is None:
          key = self.key
      # this is for use in crossattn
      c = batch[key][:, None]
      c = self.embedding(c)
      return c
  
imports: import torch
  import torch.nn
  from functools import partial
  import clip
  from einops import rearrange, repeat
  from transformers import CLIPTokenizer, CLIPTextModel
  import kornia
  from ldm.modules.x_transformer import Encoder, TransformerWrapper
label_desc: Use image node_id 2 for calling the ClassEmbedder obj's underlying member method code with example usage: obj.forward(batch, key) and returns: c