function pendingConcur(uint _pid, address _user) external view returns (uint) {
	...
	// take the minimum of endBlock and currentBlock
	uint endRewardBlock = endBlock >= block.number ? block.number : endBlock;
	if (endRewardBlock > pool.lastRewardBlock && lpSupply != 0) {
		uint multiplier = getMultiplier(pool.lastRewardBlock, endRewardBlock);
		...
	}
	...
}
