* or outgoing. Default is false.
*/
public Object getConstraint(Object key, Object cell, Object edge,
boolean source)
{
mxCellState state = graph.getView().getState(cell);
Map<String, Object> style = (state != null) ? state.getStyle() : graph
.getCellStyle(cell);
return (style != null) ? style.get(key) : null;
}