lines = linesStream.collect(toImmutableList());
    }

    assertTrue(source.wasStreamClosed());
    assertEquals(SPLIT_LINES, lines);
  }

  public void testCopyTo_appendable() throws IOException {
    StringBuilder builder = new StringBuilder();

    assertEquals(STRING.length(), source.copyTo(builder));
    assertTrue(source.wasStreamOpened() && source.wasStreamClosed());

      writer.write(buf, 0, read);
    }
    reader.close();
    writer.close();

    assertTrue(source.wasStreamClosed());
    assertEquals(STRING, writer.toString());
  }

  public void testCopyTo_appendable() throws IOException {
    StringBuilder builder = new StringBuilder();

    assertEquals(STRING.length(), source.copyTo(builder));
    assertTrue(source.wasStreamOpened() && source.wasStreamClosed());