class_docstr: emotion keras solver 
class_docstr_tok: ["emotion","keras","solver"]
docstr: input function for tf.data.Dataset
docstr_tok: ["input","function","for","tf.data.Dataset"]
code: def input_fn(self, mode):
      """input function for tf.data.Dataset"""
      super().input_fn(mode)
      assert self.task
      self.batch_input_shape = self.task.batch_input_shape()
      return None, self.task
  
imports: import librosa
  from absl import logging
  import delta.compat
  from tensorflow.keras import backend
  from tensorflow.python.keras.utils import losses_utils
  from delta import utils
  from delta.utils.solver.estimator_solver import EstimatorSolver
  from delta.utils.solver.utils.callbacks import ClassReportCallBack
  from delta.utils.solver.asr_solver import AsrSolver
  from delta.utils.register import registers
label_desc: Use image node_id 3 for calling the EmoKerasSolver obj's underlying member method code with example usage: obj.input_fn(mode) and returns: None,  self