public void setDrawColorTransformer(Function<E, Color> transformer) {
		this.drawColorTransformer = Objects.requireNonNull(transformer);
	}
Sets the color provider to use when drawing this edge.  This is also the color used to paint 
an 'emphasized' edge. 
@param transformer the color provider
Ghidra/Framework/Graph/src/main/java/ghidra/graph/viewer/edge/VisualEdgeRenderer.java