RFC: reproducer for missing default namespace on root element

[signed]

I started to look into how to use the library and played with the defaultNamespace setting. I expected the default namespace to be added to the root element, even in case the root element is in another namespace. Should the test case run green, or am I missing some information?

Type of change:

• [ ] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] Documentation update