empty(t, "TestWriteTo (2)", &b, s, make([]byte, len(testString)))
	}
}

func TestWriteAppend(t *testing.T) {
	var got Buffer
	var want []byte
	for i := 0; i < 1000; i++ {
		b := got.AvailableBuffer()
		b = strconv.AppendInt(b, int64(i), 10)
		want = strconv.AppendInt(want, int64(i), 10)
		got.Write(b)
	}
	if !Equal(got.Bytes(), want) {
		t.Fatalf("Bytes() = %q, want %q", &got, want)
	}

func (b *Buffer) Bytes() []byte { return b.buf[b.off:] }

// AvailableBuffer returns an empty buffer with b.Available() capacity.
// This buffer is intended to be appended to and
// passed to an immediately succeeding [Buffer.Write] call.
// The buffer is only valid until the next write operation on b.
func (b *Buffer) AvailableBuffer() []byte { return b.buf[len(b.buf):] }