ruby on rails - How to configure a custom 400 response with thin? -

I am using thin as my web server in Rail application, throwing a URL thin When trying to

  Invalid request: Invalid HTTP format, parsing fails.  Thin    
 How can custom 400 response handlers with 
 

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Update the NGN configuration file below and create a 400.html file in the public folder.

  server {80; Root / Public; # & Lt; --- Make sure to point to 'Public'! Error_page 400/40000; Location = /400.html {internal; } Place / {400 returns; }}