class_docstr: Embedding extractor from a layer
  Args:
      model (`nn.Module`):
          Model used for inference.
docstr: Registration for embedding extraction.
  Args:
      layer_name (`str`):
          Name of the layer from which the embedding is extracted.
code: def register(self, layer_name: str):
      """
      Registration for embedding extraction.
      Args:
          layer_name (`str`):
              Name of the layer from which the embedding is extracted.
      """
      if layer_name in self.modules_dict:
          layer = self.modules_dict[layer_name]
          layer.register_forward_hook(self.emb_out)
      else:
          raise ValueError("layer_name not in modules")
  
file_path: towhee/towhee/models/embedding/embedding_extractor.py
imports: import pprint
label_desc: Use image node_id 3 for calling the EmbeddingExtractor obj's underlying member method code with example usage: obj.register(layer_name) without return types