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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 decode_step(self, step_input, states):
 """One step decoding of the translation model. Parameters step_input : NDArray Shape (batch_size,) states : list of NDArrays Returns ------- step_output : NDArray Shape (batch_size, C_out) states : list step_additional_outputs : list Additional outputs of the step, e.g, the attention weights """

        step_output, states, step_additional_outputs =\
            self.decoder(self.tgt_embed(step_input), states)
        step_output = self.tgt_proj(step_output)
        return step_output, states, step_additional_outputs