@Test
public void testMergeNodes() throws Exception {

    List<Node> fromParents = new ArrayList<>();
    fromParents.add(ManifestTestUtils.createNode(
            "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n" +
                    "                     <sentinel3:alongtrackCoordinate>6059</sentinel3:alongtrackCoordinate>").getFirstChild());
    fromParents.add(ManifestTestUtils.createNode(
            "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n" +
                    "                     <sentinel3:alongtrackCoordinate>6239</sentinel3:alongtrackCoordinate>").getFirstChild());
    fromParents.add(ManifestTestUtils.createNode(
            "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n" +
                    "                     <sentinel3:alongtrackCoordinate>6419</sentinel3:alongtrackCoordinate>").getFirstChild());
    Document manifest = ManifestTestUtils.createDocument();
    final Element manifestElement = manifest.createElement("sentinel3:alongtrackCoordinate");
    manifest.appendChild(manifestElement);
    new AlongTrackCoordinateMerger().mergeNodes(fromParents, manifestElement, manifest);
    assertEquals(0, manifestElement.getAttributes().getLength());
    assertEquals(1, manifestElement.getChildNodes().getLength());
    assertEquals("6059", manifestElement.getFirstChild().getNodeValue());
    assertEquals("6059", manifestElement.getTextContent());
}