Just changing somme small parts you could achieve:
def make_colorbar(cmap, clim, orientation = 'horizontal', position = 'top', colorbar_opts = {}, **kwargs):
## create an invisible hv.Heatmap plot just to use its colorbar
hm = hv.HeatMap([(0, 0, clim[0]), (0, 1, clim[1])])
kwargs.update(dict(colorbar=True,
colorbar_opts=colorbar_opts,
clim=clim,
alpha=0,
show_frame=False,
frame_height=0,
colorbar_position=position,
toolbar="disable",
margin=(-20,0),
cmap=cmap,))
return hm.opts(**kwargs)
# set the legend_pane object as the Layout of node_bar + edge_cbar
self.legend_pane.object = (node_cbar+edge_cbar).opts(toolbar=None)
window = pn.GridSpec(ncols=3, sizing_mode="stretch_both", min_height=0)