def measure_strehl(HDUlist_or_filename=None, ext=0, slice=0, center=None,
    display=True, verbose=True, cache_perfect=False):
    """ Measure Strehl for a PSF

    NOTE - deprecated / removed function.  Moved to webbpsf package instead.

    This stub is just here to provide information on that transfer,
    and will be removed in a future version of poppy.
    """
    import warnings
    warnings.warn(
        'measure_strehl function has been deprecated and moved to webbpsf instead of poppy.'
        , DeprecationWarning)
    raise NotImplementedError(
        "The 'measure_strehl' function has been moved from the 'poppy' package to the 'webbpsf' package. "
         + 'See https://github.com/mperrin/poppy/issues/138')
