The size of each action fluent in canonical order.

        Returns:
            Sequence[Sequence[int]]: A tuple of tuple of integers
            representing the shape and size of each fluent.

def action_size(self) -> Sequence[Sequence[int]]:
        '''The size of each action fluent in canonical order.

        Returns:
            Sequence[Sequence[int]]: A tuple of tuple of integers
            representing the shape and size of each fluent.
        '''
        fluents = self.domain.action_fluents
        ordering = self.domain.action_fluent_ordering
        return self._fluent_size(fluents, ordering)