def __add__(self, other):
        # If necessary we transform both delivery times to the same base (hours)
        if self.unit != other.unit:
            a = self.as_hours()
            b = other.as_hours()
            unit_new = DELIVERY_TIME_UNIT_HOURS
        else:
            a = self
            b = other
            unit_new = self.unit

        # Now we can add both
        min_new = a.min + b.min
        max_new = a.max + b.max
        unit_new = a.unit

        return self._get_instance(min=min_new, max=max_new, unit=unit_new)
Initialize the dictionary of collations by querying the catalogs
dataset/ETHPy150Open diefenbach/django-lfs/lfs/catalog/models.py/DeliveryTimeBase.__add__--crossover with--dataset/ETHPy150Open perseas/Pyrseas/pyrseas/dbobject/collation.py/CollationDict._from_catalog