code: def add_access_key_permissions(self, access_key_id, permissions):
          
          # Get current state via HTTPS.
          current_access_key = self.get_access_key(access_key_id)
  
          # Copy and only change the single parameter.
          payload_dict = KeenApi._build_access_key_dict(current_access_key)
  
          # Turn into sets to avoid duplicates.
          old_permissions = set(payload_dict["permitted"])
          new_permissions = set(permissions)
          combined_permissions = old_permissions.union(new_permissions)
          payload_dict["permitted"] = list(combined_permissions)
  
          # Now just treat it like a full update.
          return self.update_access_key_full(access_key_id, **payload_dict)
docs: Adds to the existing list of permissions on this key with the contents of this list.
          Will not remove any existing permissions or modify the remainder of the key.
  
          :param access_key_id: the 'key' value of the access key to add permissions to
          :param permissions: the new permissions to add to the existing list of permissions