Sail.set(:my_model_setting, "Post")
Sail.set(:my_model_setting, Post)

Sail.get(:my_model_setting)
=> Post
Sail.get(:my_model_setting) do |setting_value|
  puts setting_value
end
=> Post

class ArticlesController < ApplicationController
  def index
    Sail.get(:model_for_articles).where(author: "John")
  end
end