Add a test for xmp node in java

Author: Dmitry Radchuk

kernel/src/test/java/com/itextpdf/kernel/xmp/impl/XMPNodeTest.java

@@ -0,0 +1,22 @@
+package com.itextpdf.kernel.xmp.impl;
+
+import com.itextpdf.kernel.xmp.XMPException;
+import com.itextpdf.kernel.xmp.options.PropertyOptions;
+import com.itextpdf.test.AssertUtil;
+import com.itextpdf.test.ExtendedITextTest;
+import com.itextpdf.test.annotations.type.UnitTest;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+
+@Category(UnitTest.class)
+public class XMPNodeTest extends ExtendedITextTest {
+    @Test
+    public void test() throws XMPException {
+        XMPNode node = new XMPNode("rdf:RDF", "idk", new PropertyOptions());
+        node.addChild(new XMPNode("rdf:Description", "idk", new PropertyOptions()));
+        for (Object object : node.getUnmodifiableChildren()) {
+            AssertUtil.doesNotThrow(() ->
+                    node.addChild(new XMPNode("xmp:Authors", "itext", new PropertyOptions().setArrayAlternate(true))));
+        }
+    }
+}

sharpenConfiguration.xml

@@ -416,6 +416,7 @@
             <file path="com/itextpdf/kernel/xmp/XmlDomWriter.java"/>
             <file path="com/itextpdf/kernel/xmp/XMPDateTime.java"/>
             <file path="com/itextpdf/kernel/xmp/XMPDateTimeFactory.java"/>
+            <file path="com/itextpdf/kernel/xmp/impl/XMPNodeTest.java"/>
             <!-- layout -->
             <fileset reason="XMLReader has different implementation in .NET and Java">
                 <file path="com/itextpdf/layout/hyphenation/PatternParser.java"/>