In this example contract: https://github.com/OpenZeppelin/zeppelin-solidity/blob/master/contracts/token/ERC721/ERC721Token.sol
The removeToken method is supposed to delete a token; the token _tokenId no longer exists. So why does it do
tokenOwner[_tokenId] = 0; instead of
Surely setting the value to 0 does not actually delete it? Wouldn't that mean that the contract will always take more storage space, never going down, even when the tokens are burnt?