function mint(address _tokenHolder, uint256 _amount, bytes _operatorData) external onlyOwner {
    requireMultiple(_amount);
    require(mTotalSupply.add(_amount) <= mTotalSupplyCap);

    mTotalSupply = mTotalSupply.add(_amount);
    mBalances[_tokenHolder] = mBalances[_tokenHolder].add(_amount);

    callRecipient(msg.sender, address(0), _tokenHolder, _amount, "", _operatorData, true);

    emit Minted(msg.sender, _tokenHolder, _amount, _operatorData);
    if (mErc20compatible) {
      emit Transfer(0x0, _tokenHolder, _amount);
    }
  }