'Saves traversible space along with nodes generated on the graph. Takes
the seed as input.'

def _debug_save_map_nodes(self, seed):

    img_path = os.path.join(self.logdir, '{:s}_{:d}_graph.png'.format(self.building_name, seed))
    node_xyt = self.to_actual_xyt_vec(self.task.nodes)
    plt.set_cmap('jet')
    (fig, ax) = utils.subplot(plt, (1, 1), (12, 12))
    ax.plot(node_xyt[:, 0], node_xyt[:, 1], 'm.')
    ax.set_axis_off()
    ax.axis('equal')
    if (self.room_dims is not None):
        for (i, r) in enumerate((self.room_dims['dims'] * 1)):
            min_ = (r[:3] * 1)
            max_ = (r[3:] * 1)
            (xmin, ymin, zmin) = min_
            (xmax, ymax, zmax) = max_
            ax.plot([xmin, xmax, xmax, xmin, xmin], [ymin, ymin, ymax, ymax, ymin], 'g')
    ax.imshow(self.traversible, origin='lower')
    with fu.fopen(img_path, 'w') as f:
        fig.savefig(f, bbox_inches='tight', transparent=True, pad_inches=0)
