<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def get_size(self_or_cls, plot):
 """ Return the display size associated with a plot before rendering to any particular format. Used to generate appropriate HTML display. Returns a tuple of (width, height) in pixels. """

        if isinstance(plot, Plot):
            plot = plot.state
        elif not isinstance(plot, Model):
            raise ValueError('Can only compute sizes for HoloViews '
                             'and bokeh plot objects.')
        return compute_plot_size(plot)