'Receive a result-row column value to be converted.
Subclasses should implement this method to operate on data
fetched from the database.
Subclasses override this method to return the
value that should be passed back to the application,
given a value that is already processed by
the underlying :class:`.TypeEngine` object, originally
from the DBAPI cursor method ``fetchone()`` or similar.
The operation could be anything desired to perform custom
behavior, such as transforming or serializing data.
This could also be used as a hook for validating logic.
:param value: Data to operate upon, of any type expected by
this method in the subclass.  Can be ``None``.
:param dialect: the :class:`.Dialect` in use.
This operation should be designed to be reversible by
the "process_bind_param" method of this class.'

def process_result_value(self, value, dialect):

    raise NotImplementedError()
