change equal and unequal comparison comperator in dni metamodel

tools.descartes.dni.core/model/DNIMM3.xcore

@@ -25,7 +25,7 @@ abstract class Identifier {
 	// TODO: make sure this is globally unique - with ocl?
 	readonly String uid_generated get {
 
-		if (uid == null || uid.isEmpty) {
+		if (uid === null || uid.isEmpty) {
 			uid = EcoreUtil.generateUUID().toString
 		}
 		return uid
@@ -55,10 +55,10 @@ class Node extends Entity {
 	contains IType[1] sdntype
 	unsettable boolean isPhysical = "true"
 	readonly volatile derived boolean isPhysical_derived get {
-		if (isHostedOn != null) { // not physical
+		if (isHostedOn !== null) { // not physical
 			isPhysical = false;
 		}
-		if (isHostedOn == null) {
+		if (isHostedOn === null) {
 			isPhysical = true;
 		}
 		isPhysical = true;
@@ -97,8 +97,8 @@ class Link extends Entity {
 		}
 		if (connects.size() == 1) {
 			name = "Partially_connected_" + uid
-		} else if (connects.get(0) == null || connects.get(0).name == null || connects.get(1) == null ||
-			connects.get(1).name == null) {
+		} else if (connects.get(0) === null || connects.get(0).name === null || connects.get(1) === null ||
+			connects.get(1).name === null) {
 			name = "Partially_connected_" + uid
 		} else {
 			name = "Link_" + connects.get(0).name + "<-->" + connects.get(1).name
@@ -113,7 +113,7 @@ class NetworkInterface extends AddressableEntity, NamedElement, Entity {
 	contains PerformanceNetworkInterface performance
 	container Node node opposite interfaces
 	readonly String name_generated get {
-		if (description == null || description.isEmpty) {
+		if (description === null || description.isEmpty) {
 			name = "Unnamed_iface_" + "[" + node.name + "]";
 		}
 		// else if(name==null || name.isEmpty){