func (c *C) Fatalf(format string, args ...interface{})
func TestMyFunction(c *gocheck.C) { expected := 42 actual := MyFunction() if actual != expected { c.Fatalf("Expected %d but got %d", expected, actual) } }In this example, the test will fail if the actual value returned by "MyFunction()" is not equal to 42. If this happens, "c.Fatalf()" will print a message and exit the test function immediately. Overall, the "launchpad.net/gocheck" package is a useful library for writing concise and effective tests in Go.