title: How to perform union of 2 lists?
body: <p>I have two ArrayLists ar1 and ar2.</p>
  
  <p><code>ArrayList ar1</code> contains a list of objects with each object having attributes ID, NAME and STATUS.
  <code>ArrayList ar2</code> contains a list of objects with each object having attributes ID, NAME and SUBJECT.
  Both ar1 and ar2 are of the same size.</p>
  
  <p>Is there any way by which I can merge the two lists into a new list ar3 which contains a list of objects with each object having attributes ID, NAME, STATUS and SUBJECT?</p>
  
  <p><strong>Update</strong>: ID and NAME is same in both the lists.</p>