':param serializer_class: allows you to overwrite the serializer class'

def __init__(self, serializer_class=None, activity_class=None, **options):

    self.serializer_class = (serializer_class or self.default_serializer_class)
    self.options = options
    if (activity_class is not None):
        self.activity_class = activity_class
    aggregated_activity_class = options.pop('aggregated_activity_class', None)
    if (aggregated_activity_class is not None):
        self.aggregated_activity_class = aggregated_activity_class
