title: Java ArrayList remove duplicates from both the lists
body: <p>I have 2 ArrayList of custom objects. I want to remove duplicate entries from both the ArrayList. </p>
  
  <p>The objects have three fields: fName, lName, and id. If the id occurs multiple times, I want to remove from both the lists.</p>
  
  <p>How can I do that?</p>
  
  <p>I am fine with merging both the lists and removing the 2 duplicate entries as well.</p>