In following release function parameter "ERC20Basic token", i dont understand the this parameter , plz help em out .
function release(ERC20Basic token) public {
uint256 unreleased = releasableAmount(token);
require(unreleased > 0);
released[token] = released[token].add(unreleased);
token.safeTransfer(beneficiary, unreleased);
Released(unreleased);
}