<html><head><meta name="color-scheme" content="light dark"></head><body><pre style="word-wrap: break-word; white-space: pre-wrap;">\cs_new:Npn \foo_bar:Nn #1#2
{
  \cs_if_exist:NTF#1  % warning on this line
    { \__foo_bar:n {#2} }
    { \__foo_bar:nn{#2}{literal} }  % warning on this line
}
</pre></body></html>