Duplicate @as Attribute

In XMIR, object should not have @as attributes duplicated inside.

Incorrect:

<o base="foo">
  <o base="f1" as="bar"/>
  <o base="f1" as="bar"/>
</o>

Correct:

<o base="foo">
  <o base="f1" as="bar"/>
  <o base="f1" as="buzz"/>
</o>

Published on Mon May 26 13:15:58 UTC 2025.