create_mailer_file

# File actionmailer/lib/rails/generators/mailer/mailer_generator.rb, line 9
      def create_mailer_file
        template "mailer.rb", File.join('app/mailers', class_path, "#{file_name}.rb")
        if self.behavior == :invoke
          template "application_mailer.rb", 'app/mailers/application_mailer.rb'
        end
      end