search_for_file

# File activesupport/lib/active_support/dependencies.rb, line 84
    def self.search_for_file(relpath)
      relpath += ".rb" unless relpath.end_with?(".rb")
      autoload_paths.each do |autoload_path|
        abspath = File.join(autoload_path, relpath)
        return abspath if File.file?(abspath)
      end
      nil
    end