class_docstr: Base class for speech recognition problems.
code: def feature_encoders(self, _):
      return {
          "inputs": None,  # Put None to make sure that the logic in
          # decoding.py doesn't try to convert the floats
          # into text...
          "waveforms": audio_encoder.AudioEncoder(),
          "targets": ByteTextEncoderWithEos(),
      }
  
imports: import numpy
  from tensor2tensor.data_generators import audio_encoder
  from tensor2tensor.data_generators import problem
  from tensor2tensor.data_generators import text_encoder
  from tensor2tensor.layers import common_audio
  from tensor2tensor.layers import common_layers
  from tensor2tensor.layers import modalities
  from tensor2tensor.utils import metrics
  import tensorflow.compat.v1
label_desc: Use image node_id 5 for calling the SpeechRecognitionProblem obj's underlying member method code with example usage: obj.feature_encoders(_) and returns: dict