}
vs.setEdgeAppearanceCalculator(eac);
// add global appearance
VisualMappingManager vmm = Cytoscape.getVisualMappingManager();
GlobalAppearanceCalculator gac = vmm.getVisualStyle().getGlobalAppearanceCalculator();
gac.setDefaultBackgroundColor(new Color(new Float(1.0), new Float(1.0), new Float(1.0)));
vs.setGlobalAppearanceCalculator(gac);
return vs;
}