Added some log msg into methods updatePOS() and doItHelper(). Fixed a bug in case 3 of method doItHelper(). Redesigned the test cases for case 1 and case 3.2 of method doItHelper().
1) Added key word Override to all methods override a method in parent class in all class. 2) Replaced the implementation of hashCode() method in all classes by an implementation using the HashCodeBuilder from Apache Commons Lang library.