# File test/unit/assertions.rb, line 65
                        def assert_raises(expected_exception_klass, message="")
                                _wrap_assertion {
                                        assert_instance_of(Class, expected_exception_klass, "Should expect a class of exception")
                                        actual_exception = nil
                                        full_message = build_message(message, expected_exception_klass) {
                                                | arg |
                                                "<#{arg}> exception expected but none was thrown"
                                        }
                                        assert_block(full_message) {
                                                thrown = false
                                                begin
                                                        yield
                                                rescue Exception => thrown_exception
                                                        actual_exception = thrown_exception
                                                        thrown = true
                                                end
                                                thrown
                                        }
                                        full_message = build_message(message, expected_exception_klass, actual_exception) {
                                                | arg1, arg2 |
                                                "<#{arg1}> exception expected but was\n" +
                                                arg2
                                        }
                                        assert_block(full_message) {
                                                expected_exception_klass == actual_exception.class
                                        }
                                        actual_exception
                                }
                        end