input: From the given instruction and Python code that removes duplicate elements from a list of integers, address the following query in English:
  To remove duplicates from a list of integers, the provided code initializes an empty list called `final_list` and iteratively checks if each element of the original list is already present in `final_list`. If not, it appends the element to `final_list`. This process prints a list containing only unique elements after iterating through all elements in the input list.
  
  What is the core function of the code snippet provided?
output:     
      final_list = []
      for num in numbers:
          if num not in final_list:
              final_list.append(num)
      return final_list
  