code: @Test public void cloneMultipleSegments() throws Exception {
    OkBuffer original=new OkBuffer();
    original.writeUtf8(repeat('a',Segment.SIZE * 3));
    OkBuffer clone=original.clone();
    original.writeUtf8(repeat('b',Segment.SIZE * 3));
    clone.writeUtf8(repeat('c',Segment.SIZE * 3));
    assertEquals(repeat('a',Segment.SIZE * 3) + repeat('b',Segment.SIZE * 3),original.readUtf8(Segment.SIZE * 6));
    assertEquals(repeat('a',Segment.SIZE * 3) + repeat('c',Segment.SIZE * 3),clone.readUtf8(Segment.SIZE * 6));
  }
  