Abstract base class for Hypergrid data models.
The cascading data model consists of a data owner module at the bottom with zero or more data transformer modules attached.
The data owner module should extend from datasaur-owner (which extends from this class, datasaur-base), while the transformer modules should extend directly from this class.
datasaur-base@3.0.0 together with datasaur-local3.0.0 implements the data model interface with fallbacks, superseding fin-hypergrid-data-source-base (which will no longer be maintained).
Hypergrid v2 "data controllers" are no longer supported by Hypergrid v3 and are no longer supported by the data model. In their place, data models now accept interface setup from the application, which should include a dispatchEvent method which data models call to trigger events in Hypergrid and on the application.