input: Write a function to remove duplicate elements from a list of integers. The function should take a list of integers as input and return a new list with all duplicate elements removed.
  
  def remove_duplicates(list_of_integers):
      final_list = []
      for num in list_of_integers:
          if num not in final_list:
              final_list.append(num)
      return final_list
  
  assert remove_duplicates([1, 2, 3, 2, 4, 5, 6, 3]) == [1, 2, 3, 4, 5, 6]
  assert remove_duplicates([5, 5, 5, 5]) == [5]
  assert remove_duplicates([]) == []
  assert remove_duplicates([1, 1, 2, 2, 3, 3]) == [1, 2, 3]
  assert remove_duplicates([1, 2, 3, 4, 5]) == [1, 2, 3, 4, 5]
output: def remove_duplicates(list_of_integers):
      final_list = []
      for num in list_of_integers:
          if num not in final_list:
              final_list.append(num)
      return final_list