/**
 * This class represents the exporter metadata that will be sent in your evaluation data collector
 */
export declare class ExporterMetadata {
    private metadata;
    /**
     * Add a metadata to the exporter
     * @param key - the key of the metadata
     * @param value - the value of the metadata
     */
    add(key: string, value: string | boolean | number): ExporterMetadata;
    /**
     * Return the metadata as an immutable object
     * @returns the metadata as an immutable object
     */
    asObject(): Record<string, string | boolean | number>;
}