https://www.linuxtopia.org/online_books/eclipse_documentation/eclipse_platform_plug-in_developer_guide/topic/org.eclipse.platform.doc.isv/reference/api/org/eclipse/core/commands/eclipse_platform_plugin_NotHandledException.html
Eclipse Plug-in Developer Guide (Galileo) - NotHandledException (Eclipse Platform API Specification)
Eclipse Platform Plugin Development Guide
plug indeveloper guideplatform apieclipsegalileo