contract BurnableToken is BasicToken {

    event Burn(address indexed burner, uint256 value);

  /**
   * @dev Burns a specific amount of tokens.
   * @param _value The amount of token to be burned.
   */
    function burn(uint256 _value) public {
        _burn(msg.sender, _value);
    }

    function _burn(address _who, uint256 _value) internal {
        require(_value <= balances[_who]);

        balances[_who] = balances[_who].sub(_value);
        totalSupply_ = totalSupply_.sub(_value);
        emit Burn(_who, _value);
        emit Transfer(_who, address(0), _value);
    }
}
function burn(uint256 _value) public {
        _burn(msg.sender, _value);
    }
/**
 * @dev Burns a specific amount of tokens.
 * @param _value The amount of token to be burned.
 */