What happened to freemarker list map?

After reading the document, I also checked the freemaerker example. Exam. Is ineffective. Where did I go wrong. Note.

<# List Infos? Keys as key>
<# If key. Key? Keys ???>
<# List key. Key? Keys as prop>

</# List>
</# If>
</# List>

Don't laugh. I know where I went wrong. I really don't know where the error is. Haha ..

The system blindly reports:

Freemarker. template. templateexception: Expected hash. Key evaluated instead ,,,

Always said no value. No. I will debug it again.