input: Write a function to remove all duplicate elements from a given list while preserving the original order. The function should return a new list with only the unique elements in the order they first appeared.
  def remove_duplicates(nums):
      new_list = []
      for num in nums:
          if num not in new_list:
              new_list.append(num)
      return new_list
  
  assert remove_duplicates([1, 3, 3, 5, 5, 7]) == [1, 3, 5, 7]
  assert remove_duplicates([]) == []
  assert remove_duplicates([1, 1, 1, 1]) == [1]
  assert remove_duplicates([5, 4, 3, 2, 1, 1, 2, 3, 4, 5]) == [5, 4, 3, 2, 1]
  assert remove_duplicates([1, 2, 3, 4, 5]) == [1, 2, 3, 4, 5]
output: def remove_duplicates(nums):
      new_list = []
      for num in nums:
          if num not in new_list:
              new_list.append(num)
      return new_list