Request the names for all active, configured inputs on the device.

        Once we learn how many inputs are configured, this function is called
        which will ask for the name of each active input.

def _populate_inputs(self, total):
        """Request the names for all active, configured inputs on the device.

        Once we learn how many inputs are configured, this function is called
        which will ask for the name of each active input.
        """
        total = total + 1
        for input_number in range(1, total):
            self.query('ISN'+str(input_number).zfill(2))