Atom and Base

In XMIR, inside <o/>, both, @atom and @base cannot co-exist.

Incorrect:

<program>
  <objects>
    <o>
      <o name="foo" base="bar" atom="org.eolang.number"/>
    </o>
  </objects>
</program>

Correct:

<program>
  <objects>
    <o>
      <o name="foo" atom="org.eolang.number"/>
    </o>
  </objects>
</program>

or:

<program>
  <objects>
    <o>
      <o name="foo" base="bar"/>
    </o>
  </objects>
</program>