:return: True if self is in a global memory of annotations.

def in_memory(self):
        """
        :return: True if self is in a global memory of annotations.
        """

        self_class = self.__class__
        # check if self class is in global memory
        memory = Annotation.__ANNOTATIONS_IN_MEMORY__.get(self_class, ())
        # check if self is in memory
        result = self in memory

        return result