bokeh multiple figures with shared legend

Question

When following the bokeh docs for making gridplots, if I use figure's legend keyword argument I get a legend inside each subplot. How could I get a shared legend for the entire gridplot? Further, how could I get a shared legend between say 3 out of 4 of the subplots?

Answer 1

As of Bokeh 0.13.0, it is not possible to share legends between plots, nor to have legends contain renderers from outside the plot they are defined on. There is an open issue on GitHub you can follow for updates.

Answer 2

Since there is no official support.
Here is an advice that barely qualifies as an answer -

You can plot one extra empty figure in your grid with legends ON
which can act as a reference for your plots where legend is OFF.