'Evaluates a given function using the provided available stats.'

def _run_evaluator(self, func, stats):

    host_stats = stats['host_stats']
    host_caps = stats['host_caps']
    extra_specs = stats['extra_specs']
    qos_specs = stats['qos_specs']
    volume_stats = stats['volume_stats']
    result = evaluator.evaluate(func, extra=extra_specs, stats=host_stats, capabilities=host_caps, volume=volume_stats, qos=qos_specs)
    return result
