labelsToStr(labels) {
		if (labels == null) return "";

		const keys = Object.keys(labels);
		if (keys.length == 0) return "";

		return keys
			.map(key => `${this.formatLabelName(key)}=${labels[key]}`)
			.join("--")
			.replace(/[\s]/g, "_")
			.replace(/[|&:;$%@"<>()+,/?]/g, "");
	}
Convert labels to label string

@param {Object} labels
@returns {String}
@memberof CSVReporter