def validate_concrete(self):
Test that we get the correct difference between days when an
dataset/ETHPy150Open pantsbuild/pants/src/python/pants/engine/exp/struct.py/Struct.validate_concrete--crossover with--dataset/ETHPy150Open wreckage/django-happenings/tests/unit_tests/test_models.py/ModelMethodsTest.test_start_end_diff