function blockTokenFunds(address _tokenAddress, uint _amount) external onlyAuthorized {
        uint accountedTokensBalance = tokensBalance[_tokenAddress];
        require(
            _amount <= accountedTokensBalance,
            "Tokens mount to block should be less or equal than balance."
        );
        tokensBalance[_tokenAddress] = accountedTokensBalance.sub(_amount);
        blockedTokensBalance[_tokenAddress] = blockedTokensBalance[_tokenAddress].add(_amount);
        emit FundsOperation (
            address(this),
            msg.sender,
            _tokenAddress,
            _amount,
            PaymentType.Erc20,
            OperationType.Block
        );
    }