def dot(v1, v2):
    x1, y1, z1 = v1
    x2, y2, z2 = v2
    return x1 * x2 + y1 * y2 + z1 * z2
ensure default behaviour for a handler that returns None
dataset/ETHPy150Open fogleman/pg/pg/util.py/dot--crossover with--dataset/ETHPy150Open kennethreitz/grequests/tests.py/GrequestsCase.test_map_timeout_exception_handler_no_return