def METHOD_NAME(w):
    # TODO what value to fill missing widths??? Hard problem...
    # TODO short circuit this if outer widths has no variance?
    empty = 0 if self.empty == "fill" else w.mean()
    filled = w.fillna(empty)
    scale = filled.max()
    norm = filled.sum()
    if self.empty == "keep":
        w = filled
    return w / norm * scale