function recoverERC20(address token) external onlyOwner returns(bool) {
	if(minAmountRewardToken[token] != 0) revert Errors.CannotRecoverToken();

	uint256 amount = IERC20(token).balanceOf(address(this));
	if(amount == 0) revert Errors.NullValue();
	IERC20(token).safeTransfer(owner(), amount);

	return true;
}
if(minAmountRewardToken[token] != 0)
function updateRewardToken(address token, uint256 minRewardPerSecond) external onlyOwner {
function recoverERC20(address token) external onlyOwner returns(bool) {
 pledgeAvailableRewardAmounts[pledgeId] += totalRewardAmount;
 reservedReward[token] += totalRewardAmount;
function recoverERC20(address token, address recipient) external onlyOwner returns(bool) {

	uint256 amount = IERC20(token).balanceOf(address(this));
	if(amount == 0) revert Errors.NullValue();

	if(minAmountRewardToken[token] == 0) {
	 // if it is not whitelisted, we assume it is mistakenly sent, 
	   // we transfer the token to recipient
	 IERC20(token).safeTransfer(recipient, amount);
	} else {
	// revert if the owner over transfer
	if(amount >  reservedReward[token]) revert rewardReserved();
	  IERC20(token).safeTransfer(recipient, amount - reservedReward[token]);
	}

	return true;

}
