def on_conflict(self, fields: List[Union[str, Tuple[str]]], action, index_predicate: str=None):
return self.get_queryset().on_conflict(fields, action, index_predicate)<EOL>
Sets the action to take when conflicts arise when attempting
        to insert/create a new row.

        Arguments:
            fields:
                The fields the conflicts can occur in.

            action:
                The action to take when the conflict occurs.

            index_predicate:
                The index predicate to satisfy an arbiter partial index.