serialization (dtas-player) --------------------------- * objects serialize using the "to_hsh" method (like "to_hash", but omits default values) and then to YAML. We avoid exposing the fact we use Ruby (or any programming language) in any formats. * every serializable class defines a "load" singleton method which takes the output Hash of "to_hsh" * we avoid serializing default values to make the state file shorter and more suitable for human viewing and editing.