def apply_filter(x, filter=None, axis=0):
    x = _as_array(x)
    if x.shape[axis] == 0:
        return x
    b, a = filter
    return signal.filtfilt(b, a, x, axis=axis)
Test RuntimeError raised when no files of known types were found.
dataset/ETHPy150Open kwikteam/phy/phy/traces/filter.py/apply_filter--crossover with--dataset/ETHPy150Open Blazemeter/taurus/tests/modules/test_SeleniumExecutor.py/TestSeleniumStuff.test_no_supported_files_to_test