class_docstr: class of Teacher
docstr: generate soft labels per example 
docstr_tok: ["generate","soft","labels","per","example"]
code: def __call__(self, feat):
      """generate soft labels per example"""
      # shape [1, T, D, C]
      inputs = feat[np.newaxis, :, :, :]
      validate_feed = {
          self.audio_ph: inputs,
      }
      soft_label = self.sess.run(
          self.soft_label, feed_dict=validate_feed
      )
      return soft_label[0]
  
file_path: delta/delta/serving/knowledge_distilling.py
imports: import numpy
  import delta.compat
  from delta.utils.register import registers
  from delta.serving.base_frozen_model import FrozenModel
label_desc: Use image node_id 3 for calling the Teacher obj's underlying member method code with example usage: obj.__call__(feat) and returns: soft_label