def value_from_object(self, obj):
        return getattr(obj, self.attname).all()
sum of elements nums[i..j], inclusive.
dataset/ETHPy150Open django/django/django/db/models/fields/related.py/ManyToManyField.value_from_object--crossover with--dataset/ETHPy150Open algorhythms/LeetCode/303 Range Sum Query - Immutable.py/NumArray.sumRange