def __init__(self, r):
        self._rdr = r
        size = r.get_uint8()
        self._size = size
This is a check to see if the object is an instance of a type
dataset/ETHPy150Open denisenkom/pytds/pytds/tds_types.py/PlpReader.__init__--crossover with--dataset/ETHPy150Open cloudera/hue/desktop/core/ext-py/tablib-0.10.0/tablib/packages/odf/element.py/Element.isInstanceOf