}
	// Test error after ReadByte.
	_, _, err = r.ReadRune() // reset state
	if err != nil {
		t.Error("unexpected error on ReadRune (2):", err)
	}
	for range buf {
		_, err = r.ReadByte()
		if err != nil {
			t.Error("unexpected error on ReadByte (2):", err)
		}
	}
	if r.UnreadRune() == nil {
		t.Error("expected error after ReadByte")
	}
	// Test error after UnreadByte.

    v1Creator.setString(1, "BBbb")
    v1Creator.commit()

    cache["k1"]!!.use { snapshot1 ->
      val inV1 = snapshot1.getSource(0).buffer()
      assertThat(inV1.readByte()).isEqualTo('A'.code.toByte())
      assertThat(inV1.readByte()).isEqualTo('A'.code.toByte())

      val v1Updater = cache.edit("k1")!!
      v1Updater.setString(0, "CCcc")
      v1Updater.setString(1, "DDdd")
      v1Updater.commit()