"""Dependency injection example, engines module."""


class Engine:
    """Example engine base class.

    Engine is a heart of every car. Engine is a very common term and
    could be implemented in very different ways.
    """


class GasolineEngine(Engine):
    """Gasoline engine."""


class DieselEngine(Engine):
    """Diesel engine."""


class ElectricEngine(Engine):
    """Electric engine."""
