List<String> list = Lists.newArrayList("a", "b");

    // Test & Verify
    Iterator<String> i1 = Iterators.consumingIterator(list.iterator());
    Iterator<String> i2 = Iterators.consumingIterator(list.iterator());

    i1.next();
    try {
      i2.next();
      fail("Concurrent modification should throw an exception.");
    } catch (ConcurrentModificationException cme) {
      // Pass
    }
  }

    // Test & Verify
    Iterator<String> i1 = Iterables.consumingIterable(list).iterator();
    Iterator<String> i2 = Iterables.consumingIterable(list).iterator();

    i1.next();
    try {
      i2.next();
      fail("Concurrent modification should throw an exception.");
    } catch (ConcurrentModificationException cme) {
      // Pass
    }
  }

    // Test & Verify
    Iterator<String> i1 = Iterables.consumingIterable(list).iterator();
    Iterator<String> i2 = Iterables.consumingIterable(list).iterator();

    i1.next();
    try {
      i2.next();
      fail("Concurrent modification should throw an exception.");
    } catch (ConcurrentModificationException cme) {
      // Pass
    }
  }

    List<String> list = Lists.newArrayList("a", "b");

    // Test & Verify
    Iterator<String> i1 = Iterators.consumingIterator(list.iterator());
    Iterator<String> i2 = Iterators.consumingIterator(list.iterator());

    i1.next();
    try {
      i2.next();
      fail("Concurrent modification should throw an exception.");
    } catch (ConcurrentModificationException cme) {
      // Pass
    }
  }