While playing with player/stage, I often felt the necessity of drawing multiple disjoint lines in a single go. Sending them using multiple DrawLine requests caused some performance problem while debugging (I was debugging RRT algorithm i implemented, and needed to draw the tree sometimes). I changed the player api and proposed
DrawMultiline method which is very similar to DrawPolyline. I also added the necessary handlers in stage plugin.
In the attachment you can find my work.