Save the changes to the instance and any related objects.

def save(self):
        """Save the changes to the instance and any related objects."""

        # first call save with commit=False for all Forms
        for form in self._forms:
            if isinstance(form, BaseForm):
                form.save(commit=False)

        # call save on the instance
        self.instance.save()

        # call any post-commit hooks that have been stashed on Forms
        for form in self.forms:
            if isinstance(form, BaseForm):
                if hasattr(form, 'save_m2m'):
                    form.save_m2m()
                if hasattr(form, 'save_related'):
                    form.save_related()

        # call save on any formsets
        for form in self._forms:
            if isinstance(form, BaseFormSet):
                form.save(commit=True)

        return self.instance