Using the core `NotInmplementedError` is not desireable since its
documentation includes:
> Note that if `fork` raises a `NotImplementedError`, then
> `respond_to?(:fork)` returns `false`.
Since we are responding to the method but still raise an error, our
usage of the exception does not fulfill its documentation.
A custom error instead of a default `NoMethodError` is still desireable
since it significantly helps with debugging. With a different Exception,
we make it clear that a method is expected to be there and just wasn't
implemented by a subclass as opposed to the caller just using an object
wrong and calling entirely unexpected methods on it.
The global default (unless overwritten by an adapter class) is to use
the JSON encoder since it's the most versatile and flexible option for a
logger today.
An ada pert wraps a log device (e.g. a file, an underlying logger, ...)
and provides an uniform interface to write the encoded log event to its
final target.
By using a registry, we can create the required adapter instance for a
provided log device automatically.
