XML : Working with namespaces using Spin by Camunda

I´m working with Spin and I have a problem with the namespaces.

Let´s say I have the following XML:

  <root xmlns="test">      <sub></sub>  </root>    

If I read this into a SpinXmlElement using

  SpinXmlElement root = Spin.XML("<root xmlns=\"test\"><sub></sub></root>");    

<sub> is automatically in the same namespace as <root> which is "test".

Now let´s add a new Element called "sub2":

  SpinXmlElement sub2 = Spin.XML("<sub2></sub2>");  root.append(sub2);    

After a xpath-test you can see that <sub2> is in no namespace.

  try {      root.xPath("./ns:sub2").ns("ns", "test").element();  } catch (final SpinXPathException ex) {      System.out.println("This will throw an error, because <sub2> has no namespace.");  }    

Important:
If you print root via .toString() you get the following output:

  <?xml version="1.0" encoding="UTF-8"?>  <root xmlns="test">     <sub/>     <sub2 xmlns=""/>  </root>    

You can see, that <sub2> has an empty namespace here.

Now let´s add a new Element called "sub3". This time with the same namespace.

  SpinXmlElement sub3 = Spin.XML("<sub3 xmlns=\"test\"></sub3>");  root.append(sub3);    

If you do a xpath-test, you will see that <sub3> now is in the same namespace as <root> ("test").

  try {      root.xPath("./sub3").element();  } catch (final SpinXPathException ex) {      System.out.println("This will throw an error, because <sub3> has a namespace.");  }    

Important:
But if you print it again, you´ll get the following output:

  <?xml version="1.0" encoding="UTF-8"?>  <root xmlns="test">     <sub/>     <sub2 xmlns=""/>     <sub3 xmlns=""/>  </root>    

So, <sub2> and <sub3> have an empty namespace when you print them, but in reallity <sub3> has a namespace and <sub2> has not.

In the end my questions are:
1. Is this behaviour a bug or am i making mistakes? Maybe it is the correct behaviour and I´m misunderstanding things.
2. Is it possible to ignore the namespaces while working with Spin?
3. Is there a way to add an element to an existing namespace without adding the xmlns attribute in the printed form?

e.g.

  <?xml version="1.0" encoding="UTF-8"?>  <root xmlns="test">  <!-- All <sub> elements in the namespace "test" -->     <sub/>     <sub2/>     <sub3/>  </root>    

Thank you for your help in advance.

Greetings from Germany, Stefan Geiß