class_docstr: kws task 
docstr: data meta
docstr_tok: ["data","meta"]
code: def feature_spec(self):
      """data meta"""
      output_shapes = (
          tf.TensorShape([self.window_len, self.final_feat_dim]),
          tf.TensorShape([]),
      )
      output_types = (tf.float32, tf.int32)
      return output_shapes, output_types
  
file_path: delta/delta/data/task/kws_cls_task.py
imports: import struct
  import numpy
  import delta.compat
  from delta import utils
  from delta.utils.register import registers
  from delta.data.task.base_speech_task import SpeechTask
  from delta.data.utils.htk_reader_lib import HtkReaderIO
label_desc: Use image node_id 5 for calling the KwsClsTask obj's underlying member method code with example usage: obj.feature_spec() and returns: output_shapes,  output_types