case REMOVE_FIELD:
RemoveField removeField = (RemoveField) u;
System.out.println("\t- {parentId: " + removeField.getParentId() + ", id: \"" + removeField.getId() + "\"}");
break;
case REMOVE_INDEX:
RemoveIndex removeIndex = (RemoveIndex) u;
System.out.println("\t# {parentId: " + removeIndex.getParentId()+ ", id: " + removeIndex.getId() + "}");
break;
case REMOVE_CHILDREN:
RemoveChildren removeChildren = (RemoveChildren) u;
System.out.println("\t! {id: " + removeChildren.getId() + "}");
break;