You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: omniauth.rb
    path of file: ./repos/omniauth/lib
    
    the code of the file until where you have to start completion: # TODO: Fixed in https://github.com/rack/rack/pull/1610 for Rack 3
if defined?(RUBY_ENGINE) && RU
    
    def deep_merge(hash, other_hash)
      target = hash.dup

      other_hash.each_key do |key|
        if other_hash[key].is_a?(::Hash) && hash[key].is_a?(::Hash)
          target[key] = deep_merge(target[key], other_hash[key])
          next
        end

        target[key] = other_hash[key]
      end