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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 transformer_moe_prepend_8k():
 """Model which formulate a seq2seq problem as language modeling."""

  hparams = transformer_moe_8k()
  hparams.prepend_mode = "prepend_inputs_masked_attention"
  hparams.eval_drop_long_sequences = False
  hparams.max_input_seq_length = 7500
  hparams.default_ff = "sepm"
  hparams.layer_types = "locm/redm/locm-moe/redm/locm"
  hparams.moe_num_experts = 256
  return hparams