validateExemplarLabelSet(labelSet) {
		let res = '';
		for (const [labelName, labelValue] of Object.entries(labelSet)) {
			res += `${labelName}${labelValue}`;
		}
		if (res.length > 128) {
			throw new RangeError(
				'Label set size must be smaller than 128 UTF-8 chars',
			);
		}
	}
Validation for the label set format.
https://github.com/OpenObservability/OpenMetrics/blob/d99b705f611b75fec8f450b05e344e02eea6921d/specification/OpenMetrics.md#exemplars

@param {object} labelSet - Exemplar labels.
@throws {RangeError}
@return {void}