Description:
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We had a problem where importing an xsd with a namespace of PersonNS caused the single-argument version of
createDocument to stop working. No idea why, but making the namespace a proper uri:
urn:personNS
fixed the problem.

Actually namespaces *should* be uris, and uris are supposed to have a scheme, so we *should* check for a valid uri anywhere we expect a namespace. Also we should fix it in the docs if we have examples of invalid namespaces (which we do).