based on: [https://github.com/chujiezheng/chat_templates/blob/main/chat_templates/chatml.jinja]

  {% if messages[0]['role'] == 'system' %}
  {% set offset = 1 %}
{% else %}
  {% set offset = 0 %}
{% endif %}

{{ bos_token }}
{% for message in messages %}
  {% if (message['role'] == 'user') != (loop.index0 % 2 == offset) %}
      {{ raise_exception('Conversation roles must alternate user/assistant/user/assistant/...') }}
  {% endif %}

  {{ '<|im_start|>' + message['role'] + '
' + message['content'].strip() + '<|im_end|>
' }}

  {% if loop.last and message['role'] == 'user' and add_generation_prompt %}
      {{ '<|im_start|>assistant
' }}
  {% endif %}
{% endfor %}
````