// ignore
            }
        }
        cache.clear();
    }

    public void register(MavenProject project, Key key, CacheRecord record) {
        // default cache does not track extension usage
    }

    public void dispose() {
        flush();
    }

    </default>
  </defaults>
  <classes>
    <class java.clone="deep">
      <name>TrackableBase</name>
      <version>1.0.0+</version>
      <description>
        common base class that contains code to track the source for
        this instance (USER|GLOBAL)
      </description>
      <codeSegments>
        <codeSegment>
          <version>1.0.0/1.3.0</version>
          <code>

* installation
* activation
* update
* deactivation
* un-installation

When a plugin is installed we may want to check the license and make users agree. We may also want to unpack the given plugin in a particular location.

     * from the information that is available at the point the problem occurs and as such merely serves as a best effort
     * to provide information to the user to track the problem back to its origin.
     *
     * @return The identifier of the model from which the problem originated or an empty string if unknown, never
     *         {@code null}.
     */
    String getModelId();