Canonical XML standard https://www.ietf.org/rfc/rfc3076.txt contains various examples but none with the input document having a namespace on the element name.
So what is the canonical form of
<Namespace:Element Attribute="Value" xmlns:Namespace="https://namespace.example.com"/>
Is it
<Namespace:Element xmlns:Namespace="https://namespace.example.com" Attribute="Value"></Namespace:Element>
or is it
<Element xmlns="https://namespace.example.com" Attribute="Value"></Element>
or even
<Element xmlns="https://namespace.example.com" xmlns:Namespace="https://namespace.example.com" Attribute="Value"></Element>
or something else ?