assert_raises

# File lib/minitest/unit.rb, line 357
    def assert_raises *exp
      msg = "#{exp.pop}.\n" if String === exp.last

      begin
        yield
      rescue MiniTest::Skip => e
        return e if exp.include? MiniTest::Skip
        raise e
      rescue Exception => e
        expected = exp.any? { |ex|
          if ex.instance_of? Module then
            e.kind_of? ex
          else
            e.instance_of? ex
          end
        }

        assert expected, proc {
          exception_details(e, "#{msg}#{mu_pp(exp)} exception expected, not")
        }

        return e
      end

      exp = exp.first if exp.size == 1

      flunk "#{msg}#{mu_pp(exp)} expected but nothing was raised."
    end