def _fontsize(self, key, label='fontsize', common=True):
        if not self.fontsize: return {}

        if not isinstance(self.fontsize, dict):
            return {label:self.fontsize} if common else {}

        unknown_keys = set(self.fontsize.keys()) - set(self._fontsize_keys)
        if unknown_keys:
            msg = "Popping unknown keys %r from fontsize dictionary.\nValid keys: %r"
            self.warning(msg %  (list(unknown_keys), self._fontsize_keys))
            for key in unknown_keys: self.fontsize.pop(key, None)

        if key in self.fontsize:
            return {label:self.fontsize[key]}
        elif key in ['ylabel', 'xlabel'] and 'labels' in self.fontsize:
            return {label:self.fontsize['labels']}
        else:
            return {}
dataset/ETHPy150Open ioam/holoviews/holoviews/plotting/plot.py/DimensionedPlot._fontsize/original