code: def forward(self, x, skip):
      x = self.skip_linear(torch.cat([x, skip], dim=-1))
      x = self.norm(x)
  
      return x
  
imports: import math
  from typing import Optional, Union
  import torch
  from torch import nn
  from ...configuration_utils import ConfigMixin, register_to_config
  from ...models import ModelMixin
  from ...models.attention import FeedForward
  from ...models.attention_processor import Attention
  from ...models.embeddings import TimestepEmbedding, Timesteps, get_2d_sincos_pos_embed
  from ...models.normalization import AdaLayerNorm
  from ...models.transformer_2d import Transformer2DModelOutput
  from ...utils import logging
label_desc: Use image node_id 2 for calling the SkipBlock obj's underlying member method code with example usage: obj.forward(x, skip) and returns: x