// The stake modifier used to hash for a stake kernel is chosen as the stake
// modifier about a selection interval later than the coin generating the kernel
-bool GetKernelStakeModifier(uint256 hashBlockFrom, uint64_t& nStakeModifier);
+bool GetKernelStakeModifier(const uint256 &hashBlockFrom, uint64_t& nStakeModifier);
// Check whether stake kernel meets hash target
// Sets hashProofOfStake on success return