def value_for_key(tuple_of_tuples, key):
    for t in tuple_of_tuples:
        if t[0] == key:
            return t[1]
    else:
        return key
Test for transaction rollback, test one: check tiles.
dataset/ETHPy150Open CiscoSystems/avos/horizon/utils/functions.py/value_for_key--crossover with--dataset/ETHPy150Open GeoscienceAustralia/agdc/tests/test_abstract_ingester.py/TestIngester.test_rollback_one_tiles