values []interface{}
		key    string
	}{
		{[]interface{}{"a"}, "a"},
		{[]interface{}{1, 2, 3}, "1_2_3"},
		{[]interface{}{1, nil, 3}, "1_nil_3"},
		{[]interface{}{[]interface{}{1, 2, 3}}, "[1 2 3]"},
		{[]interface{}{[]interface{}{"1", "2", "3"}}, "[1 2 3]"},
		{[]interface{}{[]interface{}{"1", nil, "3"}}, "[1 <nil> 3]"},
	}
	for _, c := range cases {
		if key := ToStringKey(c.values...); key != c.key {

	{faces, "~", -1, []string{faces}},
	{faces, "", -1, []string{"☺", "☻", "☹"}},
	{"1 2 3 4", " ", 3, []string{"1 ", "2 ", "3 4"}},
	{"1 2 3", " ", 3, []string{"1 ", "2 ", "3"}},
	{"1 2", " ", 3, []string{"1 ", "2"}},
	{"123", "", 2, []string{"1", "23"}},
	{"123", "", 17, []string{"1", "2", "3"}},
}

func TestSplitAfter(t *testing.T) {
	for _, tt := range splitaftertests {
		a := SplitAfterN([]byte(tt.s), []byte(tt.sep), tt.n)