assertEquals(1, sb.index()); assertEquals(3, sb.length()); assertEquals('x', sb.charAt(0)); assertEquals('x', sb.charAt(1)); assertEquals('x', sb.charAt(2)); assertEquals('x', sb.charAt(0)); assertEquals('x', sb.charAt(1)); assertEquals('x', sb.charAt(2)); assertEquals('z', sb.charAt(3)); assertEquals('z', sb.charAt(4)); assertEquals('z', sb.charAt(5)); assertEquals('x', sb.charAt(2)); assertEquals('z', sb.charAt(3)); assertEquals('z', sb.charAt(5)); assertEquals('w', sb.charAt(6)); assertEquals('w', sb.charAt(8)); assertEquals('x', sb.charAt(2));