/**
 * Return the time it would take to redo the work difference between from and
 * to, assuming the current hashrate corresponds to the difficulty at tip, in
 * seconds.
 */
int64_t GetBlockProofEquivalentTime(const CBlockIndex &to,
                                    const CBlockIndex &from,
                                    const CBlockIndex &tip,
                                    const Consensus::Params &);
                                    
                                    
/**
 * Bitcoin cash's difficulty adjustement mechanism.
 */
uint32_t GetNextCashWorkRequired(const CBlockIndex *pindexPrev,
                                 const CBlockHeader *pblock,
                                 const Consensus::Params &params);