The file for the request (absolute pathname required).
OptionalincludeOptionalincludeThe line number for the request (1-based).
The character offset (on the line) for the request (1-based).
OptionalprefixOptional prefix to apply to possible completions.
OptionalprojectOptionaltriggerCharacter that was responsible for triggering completion.
Should be undefined if a user manually requested completion.
Optionaltrigger
Arguments for completions messages.