Swimlane names to remain visible on large diagrams 

Raised by SH/RH on Operating Model Visualisation use case

As a consumer of process models using MooD, I want a swimlane name to remain visible at all times such that I am able to identify which role is responsible for a process step.  At present, when I scroll either horizontally (for a horizontal swimlane) or vertically (for a vertical swimlane), the name of the swimlane is moved off the top of the page, or there is some other indication of the swim lane. 

Acceptance criteria is that when I scroll beyond a single visible page, the name of a swimlane remains visible, or accessible to me.