You can use operators like
+ to combine strings inside expression blocks.
If statements
If statements in Jinja look like this:
{% if message['role'] == 'user' %}
{{ message['content'] }}
{% endif %}
Note how where Python uses whitespace to mark the beginnings and ends of for and if blocks, Jinja requires you
to explicitly end them with {% endfor %} and {% endif %}.
Special variables
Inside your template, you will have access to the list of messages, but you can also access several other special
variables.