def buffer_read(self, session, count):
        raise NotImplementedError
@return: The number of key/value pairs in this Shelf
dataset/ETHPy150Open hgrecco/pyvisa/pyvisa/highlevel.py/VisaLibraryBase.buffer_read--crossover with--dataset/ETHPy150Open kuri65536/python-for-android/python-modules/twisted/twisted/persisted/dirdbm.py/DirDBM.__len__