Addded two System.outs to ezvcard.io.xml.XCardWriterTest.write_prettyPrint(), at line 601:

    System.out.println("actual=[" + actual + "]");
    System.out.println("expectedRegex=[" + expectedRegex + "]");

right before the

    assertTrue(actual.matches(expectedRegex));

Here's the result:

---

Running ezvcard.io.xml.XCardWriterTest
actual=[<?xml version="1.0" encoding="UTF-8"?>

<vcards xmlns="urn:ietf:params:xml:ns:vcard-4.0">&#13;
  <vcard>&#13;
    <fn>&#13;
      <parameters>&#13;
        <x-foo>&#13;
          <unknown>bar</unknown>&#13;
        </x-foo>&#13;
      </parameters>&#13;
      <text>John Doe</text>&#13;
    </fn>&#13;
    <group name="group">&#13;
      <note>&#13;
        <text>note</text>&#13;
      </note>&#13;
    </group>&#13;
  </vcard>&#13;
</vcards>]



expectedRegex=[<\?xml version="1.0" encoding=".*?"\?>
<vcards xmlns="urn:ietf:params:xml:ns:vcard-4.0">
  <vcard>
    <fn>
      <parameters>
        <x-foo>
          <unknown>bar</unknown>
        </x-foo>
      </parameters>
      <text>John Doe</text>
    </fn>
    <group name="group">
      <note>
        <text>note</text>
      </note>
    </group>
  </vcard>
</vcards>]


Tests run: 19, Failures: 1, Errors: 0, Skipped: 0, Time elapsed: 0.239 sec <<< FAILURE! - in ezvcard.io.xml.XCardWriterTest
write_prettyPrint(ezvcard.io.xml.XCardWriterTest)  Time elapsed: 0.011 sec  <<< FAILURE!
java.lang.AssertionError: null
	at org.junit.Assert.fail(Assert.java:86)
	at org.junit.Assert.assertTrue(Assert.java:41)
	at org.junit.Assert.assertTrue(Assert.java:52)
	at ezvcard.io.xml.XCardWriterTest.write_prettyPrint(XCardWriterTest.java:604)