This class comprises works whose essence is to enhance or add value to expressions from one or more other works without altering
them, by the selection, arrangement and/or addition of features of different form, such as layout to words, recitation and movement to
texts, performance to musical scores etc. This does not make the contents of the incorporated expressions part of the Container Work, but
only part of the resulting expression. Container Work may include the addition of new, original parts to the incorporated expressions,
such as introductions, graphics, etc. This class is an “abstract class,” in that it only serves as an umbrella for its three subclasses.
As a consequence, it can only be instantiated by instances of any of its subclasses: nothing can be an instance of it, unless it is an
instance of either F17 Aggregation Work, F19 Publication Work, or F20 Performance Work. A new version of a container work does not make
the resulting complex work a Container Work as well. The inclusion of expressions from a complex work in a Container Work does not make
the Container Work itself complex.