necessary <inherits> lines for c.g.c.collect.testModule, etc. However, adding <inherits>
            lines could make c.g.c.base.testModule transitively inherit from extra modules. If some
            of those modules are ones that it uses but forgets to list in its own <inherits>, we'd
            like to get an error. Currently we do, but if we add the extra <inherits> lines, we
            won't.

          <association>
            <type>String</type>
            <multiplicity>*</multiplicity>
          </association>
          <description><![CDATA[Artifacts in the format <code>groupId:artifactId</code>. All the ones listed here are filtered (i.e. removed) from plugin and build extension class realms,
          i.e. referencing any of those coordinates in plugin/build extension dependencies has no effect.]]>
          </description>