Avoiding conflicts if Custom_AddDocLibMenuItems-function is implemented multiple

Today I found a really helpful tip how to add custom items to the SharePoint Edit Control Block (ECB) without getting in conflict with other used Custom_AddDocLibMenuItems-function-calls (for e.g. from another deployed wsp-solution or script added in a Content Editor WebPart (in SharePoint 2010) or ScriptEditor-WebPart (in SharePoint 2013).
You can find it here in Stuart Roberts' blog: http://www.stuartroberts.net/index.php/2014/01/21/quick-tip-19