warning: non-local `impl` definition, `impl` blocks should be written at the same level as their item
   --> runtime/src/apis.rs:316:13
    |
297 | /         fn dispatch_benchmark(
298 | |             config: frame_benchmarking::BenchmarkConfig
299 | |         ) -> Result<Vec<frame_benchmarking::BenchmarkBatch>, alloc::string::String> {
    | |___________________________________________________________________________________- move the `impl` block outside of this associated function `dispatch_benchmark`
...
316 |               impl cumulus_pallet_session_benchmarking::Config for Runtime {}
    |               ^^^^^-------------------------------------------^^^^^-------
    |                    |                                               |
    |                    |                                               `Runtime` is not local
    |                    `Config` is not local
    |
    = note: an `impl` is never scoped, even when it is nested inside an item, as it may impact type checking outside of that item, which can be the case if neither the trait or the self type are at the same nesting level as the `impl`