FiatTokenV1-require.sol

function transferFrom(address _from, address _to, uint256 _value) whenNotPaused notBlacklisted(_to) notBlacklisted(msg.sender) notBlacklisted(_from) public returns (bool) {
  require(_to != address(0));
  ...
}

function approve(address _spender, uint256 _value) whenNotPaused notBlacklisted(msg.sender) notBlacklisted(_spender) public returns (bool) {
    allowed[msg.sender][_spender] = _value;
    emit Approval(msg.sender, _spender, _value);
    return true;
}