1 files changed, 6 insertions, 6 deletions
diff --git a/plugins/org.eclipse.sirius.diagram.sequence/src/org/eclipse/sirius/diagram/sequence/business/internal/elements/AbstractSequenceElement.java b/plugins/org.eclipse.sirius.diagram.sequence/src/org/eclipse/sirius/diagram/sequence/business/internal/elements/AbstractSequenceElement.java
index 4586b409eb..fedb31ae18 100644
--- a/plugins/org.eclipse.sirius.diagram.sequence/src/org/eclipse/sirius/diagram/sequence/business/internal/elements/AbstractSequenceElement.java
+++ b/plugins/org.eclipse.sirius.diagram.sequence/src/org/eclipse/sirius/diagram/sequence/business/internal/elements/AbstractSequenceElement.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2010, 2020 THALES GLOBAL SERVICES and others.
+ * Copyright (c) 2010, 2021 THALES GLOBAL SERVICES and others.
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
  * which accompanies this distribution, and is available at
@@ -12,6 +12,8 @@
  *******************************************************************************/
 package org.eclipse.sirius.diagram.sequence.business.internal.elements;
 
+import java.util.Objects;
+
 import org.eclipse.emf.common.notify.impl.AdapterImpl;
 import org.eclipse.emf.ecore.EClass;
 import org.eclipse.emf.ecore.EObject;
@@ -20,13 +22,11 @@ import org.eclipse.gmf.runtime.notation.View;
 import org.eclipse.sirius.diagram.DDiagramElement;
 import org.eclipse.sirius.diagram.business.api.query.DiagramElementMappingQuery;
 import org.eclipse.sirius.diagram.description.DiagramElementMapping;
-import org.eclipse.sirius.diagram.sequence.Messages;
+import org.eclipse.sirius.diagram.sequence.tool.internal.Messages;
 import org.eclipse.sirius.ext.base.Option;
 import org.eclipse.sirius.ext.base.Options;
 import org.eclipse.sirius.viewpoint.DSemanticDecorator;
 
-import com.google.common.base.Preconditions;
-
 /**
  * Partial abstract implementation of {@link ISequenceElement}.
  * 
@@ -50,7 +50,7 @@ public abstract class AbstractSequenceElement extends AdapterImpl implements ISe
      *            the underlying GMF View.
      */
     AbstractSequenceElement(View view) {
-        this.view = Preconditions.checkNotNull(view);
+        this.view = Objects.requireNonNull(view);
     }
 
     /**
@@ -67,7 +67,7 @@ public abstract class AbstractSequenceElement extends AdapterImpl implements ISe
      * @return true is element is a sequence diagram element
      */
     protected static final boolean isSequenceDiagramElement(DDiagramElement element, EClass mappingType) {
-        Preconditions.checkNotNull(mappingType);
+        Objects.requireNonNull(mappingType);
         boolean result = false;
         if (element != null) {
             DiagramElementMapping mapping = element.getDiagramElementMapping();