demonstrate difficulty validating DD 2.5 #3648

The DDI 2.5 test fails with this:

`src-resolve: Cannot resolve the name 'xml:lang' to a(n) 'attribute declaration' component.`

We should be exporting valid DDI 2.5.

src/test/java/edu/harvard/iq/dataverse/export/ddi/dataset-finch1-ddi-2.0.xml

@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<codeBook xmlns="http://www.icpsr.umich.edu/DDI" version="2.0">
+  <stdyDscr>
+    <citation>
+      <titlStmt>
+        <titl>Darwin's Finches</titl>
+        <IDNo agency="doi">10.5072/FK2/PCA2E3</IDNo>
+      </titlStmt>
+      <rspStmt>
+        <AuthEnty>Finch, Fiona</AuthEnty>
+      </rspStmt>
+      <biblCit>Finch, Fiona, 2015, "Darwin's Finches", http://dx.doi.org/10.5072/FK2/PCA2E3,  Root Dataverse,  V1</biblCit>
+    </citation>
+  </stdyDscr>
+</codeBook>

src/test/java/edu/harvard/iq/dataverse/util/xml/XmlValidatorTest.java

@@ -13,9 +13,17 @@ public class XmlValidatorTest {
     @Test
     public void testValidateXml() throws IOException, SAXException {
         String dir = "src/test/java/edu/harvard/iq/dataverse/export/ddi/";
-       //String codebookdir = "http://www.ddialliance.org/Specification/DDI-Codebook/2.5/XMLSchema/";
-       // assertEquals(true, XmlValidator.validateXml(dir + "dataset-finch1.xml", dir + "codebook.xsd"));
-      //  assertEquals(true, XmlValidator.validateXml(dir + "dataset-spruce1.xml", dir + "codebook.xsd"));
+
+        System.out.println("Attempting to validate a DDI 2.0 file...");
+        assertEquals(true, XmlValidator.validateXml(dir + "dataset-finch1-ddi-2.0.xml", dir + "Version2-0.xsd"));
+
+        System.out.println("Attempting to validate a DDI 2.5 file...");
+        // codebook.xsd comes from http://www.ddialliance.org/Specification/DDI-Codebook/2.5/XMLSchema/codebook.xsd
+        /**
+         * @todo Make the DDI 2.5 format we export pass validation. See
+         * https://github.com/IQSS/dataverse/issues/3648
+         */
+        assertEquals(true, XmlValidator.validateXml(dir + "dataset-finch1.xml", dir + "codebook.xsd"));
     }
 
 }