contract IContractId {
    /// @param id defined as above
    /// @param version implementation version
    function contractId() public pure returns (bytes32 id, uint256 version);
}
/// @title uniquely identifies deployable (non-abstract) platform contract
/// @notice cheap way of assigning implementations to knownInterfaces which represent system services
///         unfortunatelly ERC165 does not include full public interface (ABI) and does not provide way to list implemented interfaces
///         EIP820 still in the making
/// @dev ids are generated as follows keccak256("neufund-platform:<contract name>")
///      ids roughly correspond to ABIs
function contractId() public pure returns (bytes32 id, uint256 version);
/// @param id defined as above
/// @param version implementation version