title: Handling null in java streams with optional
body: <p>What would be the best way of handling null if we have senario like below</p>
  
  <pre><code>//mocking for demonstraton  
  studentsByCourseRoster.setUsers(null);
  
  studentsByCourseRoster.getUsers().stream().forEach(user -&gt; {
      final UserDTOv2 userDTO = new UserDTOv2();
      userDTO.populateUserDataFromUserDTO(user, groupedUsers);
      users.add(userDTO);
  });
  </code></pre>