Function resolve_block_range 

async fn resolve_block_range<P: Provider<N>, N: Network>(
    provider: &P,
    filter: &Filter,
) -> Result<Option<(u64, u64)>>

Resolves the filter’s block range to concrete block numbers.

Returns None when the filter does not target a block-number range (e.g. it filters by block hash), in which case chunking is not possible. Tags such as latest and earliest are resolved against the provider so that the common case (--to-block defaulting to latest) can still be chunked.