private void checkBoundsAfterParticipantP1DeletionOfTestCreateMessageDeletion2() {
    Bounds newDiagramElementP2Bounds = getBounds(diagramElementP2, participantP2);
    Bounds newDiagramElementP3Bounds = getBounds(diagramElementP3, participantP3);
    Bounds newDiagramElementP4Bounds = getBounds(diagramElementP4, participantP4);

    Range newCreateP4Range =
        new SequenceMessageViewQuery(getGmfEdge(createP4Edge)).getVerticalRange();
    Range newCreateP3Range =
        new SequenceMessageViewQuery(getGmfEdge(createP3Edge)).getVerticalRange();

    assertEquals(
        diagramElementP1Bounds.getX()
            + diagramElementP1Bounds.getWidth()
            + LayoutConstants.LIFELINES_MIN_X_GAP,
        newDiagramElementP2Bounds.getX());
    assertEquals(origin.y, newDiagramElementP2Bounds.getY());

    assertEquals(
        diagramElementP2Bounds.getX()
            + diagramElementP2Bounds.getWidth()
            + LayoutConstants.LIFELINES_MIN_X_GAP,
        newDiagramElementP3Bounds.getX());
    int yP3 = newCreateP3Range.getLowerBound() - newDiagramElementP3Bounds.getHeight() / 2;
    assertEquals(yP3, newDiagramElementP3Bounds.getY());

    assertEquals(
        diagramElementP3Bounds.getX()
            + diagramElementP3Bounds.getWidth()
            + LayoutConstants.LIFELINES_MIN_X_GAP,
        newDiagramElementP4Bounds.getX());
    int yP4 = newCreateP4Range.getLowerBound() - newDiagramElementP4Bounds.getHeight() / 2;
    assertEquals(yP4, newDiagramElementP4Bounds.getY());
  }
  private void checkInitialBounds() {
    assertEquals(origin.x, diagramElementP1Bounds.getX());
    assertEquals(origin.y, diagramElementP1Bounds.getY());

    assertEquals(
        diagramElementP1Bounds.getX()
            + diagramElementP1Bounds.getWidth()
            + LayoutConstants.LIFELINES_MIN_X_GAP,
        diagramElementP2Bounds.getX());
    int yP2 = createP2EdgeRange.getLowerBound() - diagramElementP2Bounds.getHeight() / 2;
    assertEquals(yP2, diagramElementP2Bounds.getY());

    assertEquals(
        diagramElementP2Bounds.getX()
            + diagramElementP2Bounds.getWidth()
            + LayoutConstants.LIFELINES_MIN_X_GAP,
        diagramElementP3Bounds.getX());
    int yP3 = createP3EdgeRange.getLowerBound() - diagramElementP3Bounds.getHeight() / 2;
    assertEquals(yP3, diagramElementP3Bounds.getY());

    assertEquals(
        diagramElementP3Bounds.getX()
            + diagramElementP3Bounds.getWidth()
            + LayoutConstants.LIFELINES_MIN_X_GAP,
        diagramElementP4Bounds.getX());
    int yP4 = createP4EdgeRange.getLowerBound() - diagramElementP4Bounds.getHeight() / 2;
    assertEquals(yP4, diagramElementP4Bounds.getY());

    // TODO : checks messages bounds.
  }