Create a new gsv.SourceCompletionContext for completion. The position where the completion occurs can be specified by position. If position is NULL, the current cursor position will be used.
a gtk.TextIter, or NULL.
a new gsv.SourceCompletionContext The reference being returned is a 'floating' reference, so if you invoke Source.completionStart with this context you don't need to unref it.
Create a new gsv.SourceCompletionContext for completion. The position where the completion occurs can be specified by position. If position is NULL, the current cursor position will be used.