def get_dataset(self, name, multi_instance=0):
        """ get a specific dataset.

        example:
        try:
            gyro_data = ulog.get_dataset('sensor_gyro')
        except (KeyError, IndexError, ValueError) as error:
            print(type(error), "(sensor_gyro):", error)

        :param name: name of the dataset
        :param multi_instance: the multi_id, defaults to the first
        :raises KeyError, IndexError, ValueError: if name or instance not found
        """
        return [elem for elem in self._data_list
                if elem.name == name and elem.multi_id == multi_instance][0]
get a specific dataset.

        example:
        try:
            gyro_data = ulog.get_dataset('sensor_gyro')
        except (KeyError, IndexError, ValueError) as error:
            print(type(error), "(sensor_gyro):", error)

        :param name: name of the dataset
        :param multi_instance: the multi_id, defaults to the first
        :raises KeyError, IndexError, ValueError: if name or instance not found