private OperationPage findDirtyPageWithOperation(Operation op, OperationGraph2D graph) {
for (OperationPage page : pages) {
if (page.getGraph() == graph) {
continue;
}
OperationFlow flow = page.getGraph().getModel().getModeledFlow();
if (flow.isDirty() && flow.contains(op)) {
return page;
}
}
return null;
}