OptionalcontextThe completion context. This is only available it the client specifies
to send this using the client capability textDocument.completion.contextSupport === true
OptionalpartialAn optional token that a server can use to report partial results (e.g. streaming) to the client.
The position inside the text document.
The text document.
OptionalworkAn optional token that a server can use to report work done progress.
Completion parameters