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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def prepare_image_question_encoder(image_feat, question, hparams):
 """Prepare encoder. Args: image_feat: a Tensor. question: a Tensor. hparams: run hyperparameters Returns: encoder_input: a Tensor, bottom of encoder stack encoder_self_attention_bias: a bias tensor for use in encoder self-attention """


  encoder_input = tf.concat([image_feat, question], axis=1)
  encoder_padding = common_attention.embedding_to_padding(encoder_input)
  ignore_padding = common_attention.attention_bias_ignore_padding(
      encoder_padding)
  encoder_self_attention_bias = ignore_padding
  encoder_decoder_attention_bias = ignore_padding
  # Usual case - not a packed dataset.
  if hparams.pos == "timing":
    question = common_attention.add_timing_signal_1d(question)
  elif hparams.pos == "emb":
    question = common_attention.add_positional_embedding(
        question, hparams.max_length, "inputs_positional_embedding",
        None)
  encoder_input = tf.concat([image_feat, question], axis=1)

  return (encoder_input, encoder_self_attention_bias,
          encoder_decoder_attention_bias)