# File lib/email_spec/matchers.rb, line 251
      def failure_message
        if @expected_subject.is_a?(String)
          "expected at least one email to have the subject #{@expected_subject.inspect} but none did. Subjects were #{@given_emails.map(&:subject).inspect}"
        else
          "expected at least one email to have a subject matching #{@expected_subject.inspect}, but none did. Subjects were #{@given_emails.map(&:subject).inspect}"
        end
      end