r := NewReader(strings.NewReader("line 1\n"))
	for i := 0; i < 2; i++ {
		l, _, err := r.ReadLine()
		if l != nil && err != nil {
			t.Fatalf("on line %d/2; ReadLine=%#v, %v; want non-nil line or Error, but not both",
				i+1, l, err)
		}
	}
}

type readLineResult struct {
	line     []byte
	isPrefix bool
	err      error
}

var readLineNewlinesTests = []struct {