int instrument_parameter_variable(timeSeries); // ... RECOMMENDED - an instrument variable storing information about a parameter of the instrument used in the measurement, the dimensions don't have to be specified if the same instrument is used for all the measurements.
            instrument_parameter_variable:long_name = "" ; // RECOMMENDED - Provide a descriptive, long name for this variable.
            instrument_parameter_variable:comment = "" ; //.. RECOMMENDED - Add useful, additional information here.

def check_instrument(self, dataset):
        '''
        int instrument_parameter_variable(timeSeries); // ... RECOMMENDED - an instrument variable storing information about a parameter of the instrument used in the measurement, the dimensions don't have to be specified if the same instrument is used for all the measurements.
            instrument_parameter_variable:long_name = "" ; // RECOMMENDED - Provide a descriptive, long name for this variable.
            instrument_parameter_variable:comment = "" ; //.. RECOMMENDED - Add useful, additional information here.
        '''
        # Check for the instrument variable
        instruments = util.get_instrument_variables(dataset)
        if not instruments:
            return Result(BaseCheck.MEDIUM, False, 'Recommended variable for instrument should exist', ['No instrument variables found'])
        results = []
        for instrument in instruments:
            test_ctx = TestCtx(BaseCheck.MEDIUM, 'Recommended attributes for instrument variable {}'.format(instrument))
            var = dataset.variables[instrument]
            test_ctx.assert_true(getattr(var, 'long_name', '') != '', 'long_name attribute should exist and not be empty')

            if hasattr(var, 'comment'):
                test_ctx.assert_true(getattr(var, 'comment', '') != '', 'comment attribute should not be empty if specified')

            results.append(test_ctx.to_result())

        return results