Hi all --

I was working with the update:apply example [1], and it throws an error:
[XPTY0004] Cannot convert xs:string to node(): "doc.xml".

I'm a little confused by this: if I modify the example, and change the last to
`db:add('existing-db', 'doc.xml')` (which is db:add#1, right?), it works fine. However, keeping the local:update and trying to use `db:add#1` generates another error:
[XPST0017] db:add(database,input[,path[,options]]): 1 argument supplied, 2-4 expected

Would someone be able to shed some light on where this is going wrong?
Thanks,
Bridger