def save_instance(form, instance, fields=None, fail_message='saved',
                  commit=True, exclude=None, construct=True):
    if construct:
        instance = construct_instance(form, instance, fields, exclude)

    if form.errors:
        raise ValueError("The %s could not be %s because the data didn't"
                         " validate." % (instance.__class__.__name__,
                                         fail_message))

    if commit and hasattr(instance, 'save'):
        # see BaseDocumentForm._post_clean for an explanation
        # if len(form._meta._dont_save) > 0:
        #    data = instance._data
        #    new_data = dict([(n, f) for n, f in data.items() if not n \
        #                    in form._meta._dont_save])
        #    instance._data = new_data
        #    instance.save()
        #    instance._data = data
        # else:
        instance.save()
    return instance
Saves bound Form ``form``'s cleaned_data into document ``instance``.
dataset/ETHPy150Open jschrewe/django-mongodbforms/mongodbforms/documents.py/save_instance