contract BasicToken is ERC20Basic {
  using SafeMath for uint256;

  // public variables
  string public name;
  string public symbol;
  uint8 public decimals = 18;

  // internal variables
  uint256 _totalSupply;
  mapping(address => uint256) _balances;

  // events

  // public functions
  function totalSupply() public view returns (uint256) {
    return _totalSupply;
  }

  function balanceOf(address addr) public view returns (uint256 balance) {
    return _balances[addr];
  }

  function transfer(address to, uint256 value) public returns (bool) {
    require(to != address(0));
    require(value <= _balances[msg.sender]);

    _balances[msg.sender] = _balances[msg.sender].sub(value);
    _balances[to] = _balances[to].add(value);
    emit Transfer(msg.sender, to, value);
    return true;
  }

  // internal functions

}
function totalSupply() public view returns (uint256) {
    return _totalSupply;
  }
// events
// public functions