Method add

lib/sqlalchemy/ext/associationproxy.py:1882–1884

(self, __element: _T, /)

        return

    def add(self, __element: _T, /) -> None:
        if __element not in self:
            self.col.add(self._create(__element))

    # for discard and remove, choosing a more expensive check strategy rather
    # than call self.creator()