Function sc_light::fetcher::cht::start_number

pub fn start_number<N>(cht_size: N, cht_num: N) -> N where
    N: AtLeast32Bit, 

Get the starting block of a given CHT. CHT 0 includes block 1...SIZE, CHT 1 includes block SIZE + 1 ... 2SIZE More generally: CHT N includes block (1 + NSIZE)...((N+1)*SIZE). This is because the genesis hash is assumed to be known and including it would be redundant.