In truffle test using js, how to set the parameters after the `contract `?

Such as WhitelistedCrowdsale.test.js in openzeppelin-solidity:

contract('WhitelistedCrowdsale', function ([_, wallet, authorized, unauthorized, anotherAuthorized]) { ... } in line 12.

why the parametes of function(...) is _, wallet, authorized, unauthorized, anotherAuthorized? Can they be other things? why?

Thanks!