@Test
  public void testUpgradeSchemaFromGemfireNamespaceWithNoLocation() throws Exception {
    String xml = "<cache version=\"8.1\" xmlns=\"http://schema.pivotal.io/gemfire/cache\"></cache>";
    Document doc = XmlUtils.createDocumentFromXml(xml);
    Element oldRoot = doc.getDocumentElement();
    assertThat(oldRoot.getAttribute(CacheXml.VERSION)).isEqualTo("8.1");
    assertThat(oldRoot.getNamespaceURI()).isEqualTo(CacheXml.GEMFIRE_NAMESPACE);

    String version = "1.0";
    doc = XmlUtils.upgradeSchema(doc, GEODE_NAMESPACE, LATEST_SCHEMA_LOCATION, version);

    Element root = doc.getDocumentElement();
    assertThat(root.getNamespaceURI()).isEqualTo(GEODE_NAMESPACE);
    assertThat(root.getAttribute(CacheXml.VERSION)).isEqualTo(version);
    assertThat(root.getAttribute("xsi:schemaLocation")).isEqualTo(GEODE_SCHEMA_LOCATION);
  }
Test method for {@link XmlUtils#changeNamespace(Node, String, String)}.
geode-core/src/test/java/org/apache/geode/management/internal/configuration/utils/XmlUtilsJUnitTest.java