- **Universal constructor**: Any class which defines a `__construct()` method should take
  exactly one parameter (`$config`), and that parameter should always be an array. Any settings
  passed to the constructor will be stored in the `$_config` property of the object.
- **Initialization / automatic configuration**: After the constructor, the `_init()` method is
  called. This method can be used to initialize the object, keeping complex logic and
  high-overhead or difficult to test operations out of the constructor. This method is called
  automatically by `Object::__construct()`, but may be disabled by passing `'init' => false` to
  the constructor. The initializer is also used for automatically assigning object properties.
  See the documentation on the `_init()` method for more details.
- **Filters**: The `Object` class implements two methods which allow an object to easily
  implement filterable methods. The `_filter()` method allows methods to be implemented as
  filterable, and the `applyFilter()` method allows filters to be wrapped around them.
- **Testing / misc.**: The `__set_state()` method provides a default implementation of the PHP
  magic method (works with `var_export()`) which can instantiate an object with a static method
  call. Finally, the `_stop()` method may be used instead of `exit()`, as it can be overridden
  for testing purposes.