code: def merge_lists(*args):
      
  
      out = {}
      for contacts in filter(None, args):
          for contact in contacts:
              out[contact.value] = contact
  
      return list(out.values())
docs: Merge an arbitrary number of lists into a single list and dedupe it
  
      Args:
          *args: Two or more lists
  
      Returns:
          A deduped merged list of all the provided lists as a single list