Multiple providers can be registered for a language. In that case providers are asked in
parallel and the results are merged.
If multiple folding ranges start at the same position, only the range of the first registered provider is used.
If a folding range overlaps with an other range that has a smaller position, it is also ignored.
A failing provider (rejected promise or exception) will
not cause a failure of the whole operation.
Register a folding range provider.
Multiple providers can be registered for a language. In that case providers are asked in parallel and the results are merged. If multiple folding ranges start at the same position, only the range of the first registered provider is used. If a folding range overlaps with an other range that has a smaller position, it is also ignored.
A failing provider (rejected promise or exception) will not cause a failure of the whole operation.