+ * This class defines the essential API of plugins as used by Components by defining the following methods:
+ *
+ * - `init` : The plugin initialization method which the owning Component calls at Component initialization time.
+ *
+ * The Component passes itself as the sole parameter.
+ *
+ * Subclasses should set up bidirectional links between the plugin and its client Component here.
+ *
+ * - `destroy` : The plugin cleanup method which the owning Component calls at Component destruction time.
+ *
+ * Use this method to break links between the plugin and the Component and to free any allocated resources.
+ *
+ * - `enable` : The base implementation just sets the plugin's `disabled` flag to `false`
+ *
+ * - `disable` : The base implementation just sets the plugin's `disabled` flag to `true`