public void Initialize(string symbol, string tokenName, ulong totalSupply, uint decimals)
{
Api.Assert(!_initialized.GetValue(), "Already initialized.");
Api.Assert(Api.GetContractOwner().Equals(Api.GetTransaction().From),
"Only owner can initialize the contract state.");
_symbol.SetValue(symbol);
_tokenName.SetValue(tokenName);
_totalSupply.SetValue(totalSupply);
_decimals.SetValue(decimals);
_balances[Api.GetTransaction().From] = totalSupply;
_initialized.SetValue(true);
}