def deepfirst(seq):
    if not isinstance(seq, (list, tuple)):
        return seq
    else:
        return deepfirst(seq[0])
Overridden GetBestSize method which will return the best
dataset/ETHPy150Open dask/dask/dask/array/core.py/deepfirst--crossover with--dataset/ETHPy150Open ContinuumIO/ashiba/enaml/enaml/wx/wx_notebook.py/wxPreferencesNotebook.GetBestSize