Static providers
----------------

Static providers are family of providers that return their values "as is".
There are four types of static providers:

    - ``Class``
    - ``Object``
    - ``Function``
    - ``Value``

All of them have the same behaviour, but usage of anyone is predicted by
readability and providing object's type.

Example:

.. code-block:: python

    """`Static` providers example."""

    from objects.providers import Class
    from objects.providers import Object
    from objects.providers import Function
    from objects.providers import Value


    # Provides class - `object`:
    cls_provider = Class(object)
    assert cls_provider() is object

    # Provides object - `object()`:
    object_provider = Object(object())
    assert isinstance(object_provider(), object)

    # Provides function - `len`:
    function_provider = Function(len)
    assert function_provider() is len

    # Provides value - `123`:
    value_provider = Value(123)
    assert value_provider() == 123