assert_raises (MiniTest::Assertions)

    # File lib/minitest/unit.rb, line 131
        def assert_raises *exp
          msg = String === exp.last ? exp.pop : nil
          should_raise = false
          begin
            yield
            should_raise = true
          rescue Exception => e
            assert(exp.any? { |ex|
                     ex.instance_of?(Module) ? e.kind_of?(ex) : ex == e.class
                   }, exception_details(e, "#{mu_pp(exp)} exception expected, not"))

            return e
          end

          exp = exp.first if exp.size == 1
          flunk "#{mu_pp(exp)} expected but nothing was raised." if should_raise
        end