Blanket trait impls [vscode]

Hey guys,
I often have the problem that I want to implement some trait but can’t exactly memorize the signatures of the individual functions. Is there a way to generate those, kinda like a snippet or auto-complete? The RLS should know them, but I struggled finding good documentation to start developing an own plugin? Is it even intender or possible to call the RLS as an distinct extension, or is only the main rust language extension supposed to communicate with the RLS?