class_docstr: main model 
code: def call(self, features, **kwargs):
      self.train = kwargs["training"]
      n_class = self.cfg["data"]["task"]["classes"]["num"]
      return self.tdnn(features, n_class, self.train)
  
file_path: delta/delta/models/kws_model.py
imports: import delta.compat
  from delta.models.base_model import RawModel
  from delta.utils.register import registers
label_desc: Use image node_id 2 for calling the TdnnKwsModel obj's underlying member method code with example usage: obj.call(features) and returns: self