@abstractmethod<EOL><INDENT>def get_remembered_identifiers(self, subject_context):<DEDENT>
pass<EOL>
Based on the specified subject context map being used to build a
Subject instance, returns any previously remembered identifier for the
subject for automatic identity association (aka 'Remember Me').

The context map is usually populated by a Subject.Builder
implementation.  See the SubjectFactory class constants for
Yosai's known map keys.

:param subject_context: the contextual data, usually provided by a
                        Builder implementation, that is being used to
                        construct a Subject instance

:returns: the remembered identifier or None if none could be acquired