Ruby on Rails 5.2.6
Module
ActionMailer::TestCase::Behavior
actionmailer/lib/action_mailer/test_case.rb
Namespace
MODULE
ActionMailer::TestCase::Behavior::ClassMethods
Included Modules
ActiveSupport::Testing::ConstantLookup
ActionMailer::TestHelper
Rails::Dom::Testing::Assertions::SelectorAssertions
Rails::Dom::Testing::Assertions::DomAssertions