appendData(f, 5, 4);
assertTrue(c.tailBody()); // finish reading the first file
assertEquals(5, q.size()); // should be 5 in queue.
assertTrue(c.tailBody()); // notice file rotation, reset
assertTrue(c.tailBody()); // attempt to open file again.
assertTrue(c.tailBody()); // read 4 lines from new file
assertFalse(c.tailBody()); // no more to read
assertEquals(9, q.size()); // should be 5 + 4 in queue.