def METHOD_NAME(dialogue_history):
    """Encode the dialogue context to the response ranking vector space.
    Args:
        dialogue_history: a list of strings, the dialogue history, in
            chronological order.
    """
    # The context is the most recent message in the history.
    context = dialogue_history[-1]
    extra_context = list(dialogue_history[:-1])
    extra_context.reverse()
    extra_context_feature = " ".join(extra_context)
    return sess.run(
        context_encoding_tensor,
        feed_dict={text_placeholder: [context], extra_text_placeholder: [extra_context_feature]},
    )[0]