Crowdsale that locks tokens from withdrawal until it ends.
function _processPurchase(address beneficiary, uint256 tokenAmount) internal
Overrides parent by storing balances instead of issuing tokens right away.
beneficiary- Token purchaser
tokenAmount- Amount of tokens purchased
function balanceOf(address account) public view returns (uint256)
- the balance of an account.
function withdrawTokens(address beneficiary) public
Withdraw tokens only after crowdsale ends.
beneficiary- Whose tokens will be withdrawn.