Map each ORM exceptions to Rango HTTP errors

[botanicus]

quiet do
  DataMapper::ObjectNotFoundError = Class.new(NotFound)
end

So you rather than:

def show(id)
  post = Post.get(id)
  raise NotFound unless post
  render "post.html", post: post
end

use just:

def show(id)
  render "post.html", post: Post.get!(id)
end

Where should I put it? Generate it to the beginning of models? Somewhere to lib/rango/orm?