Examples of valid array, slice, and map literals:
</p>

<pre>
// list of prime numbers
primes := []int{2, 3, 5, 7, 9, 2147483647}

// vowels[ch] is true if ch is a vowel
vowels := [128]bool{'a': true, 'e': true, 'i': true, 'o': true, 'u': true, 'y': true}

// the array [10]float32{-1, 0, 0, 0, -0.1, -0.1, 0, 0, 0, -1}
filter := [10]float32{-1, 4: -0.1, -0.1, 9: -1}

	f := callbackFuncs[i]
	callbackMutex.Unlock()

	if f == nil {
		panic("missing callback function")
	}
	f()
}

func testCallback(t *testing.T) {
	var x = false
	nestedCall(func() { x = true })
	if !x {
		t.Fatal("nestedCall did not call func")
	}
}

func testCallbackGC(t *testing.T) {
	nestedCall(runtime.GC)
}

func testCallbackPanic(t *testing.T) {