saves the given data to the buffer
        :param b:

def __save(self, b):
        '''
            saves the given data to the buffer
        :param b:
        '''
        newbufferidx = (self.__bufferidx + len(b))
        self.__buffer[self.__bufferidx:newbufferidx] = b
        #update buffer index
        self.__bufferidx = newbufferidx