/**
 * Represents an internal duration equivalent structure used to hold PDF duration components and serialize them.
 *
 * @private
 */
export declare class _PdfDurationEquivalent {
    /**
     * Represents the internal year component of the duration.
     *
     * @private
     */
    _years: number;
    /**
     * Represents the internal month component of the duration.
     *
     * @private
     */
    _months: number;
    /**
     * Represents the internal week component of the duration.
     *
     * @private
     */
    _weeks: number;
    /**
     * Represents the internal day component of the duration.
     *
     * @private
     */
    _days: number;
    /**
     * Represents the internal hour component of the duration.
     *
     * @private
     */
    _hours: number;
    /**
     * Represents the internal minute component of the duration.
     *
     * @private
     */
    _minutes: number;
    /**
     * Represents the internal second component of the duration.
     *
     * @private
     */
    _seconds: number;
    /**
     * Represents the internal fractional part for second precision, including the number of digits and the value.
     *
     * @private
     */
    _fractionalPart: {
        numberOfDigits: number;
        fractionalValue: number;
    };
    constructor(years?: number, months?: number, weeks?: number, days?: number, hours?: number, minutes?: number, seconds?: number, fractionalPart?: {
        numberOfDigits: number;
        fractionalValue: number;
    });
    /**
     * Converts the internal duration equivalent into a readable textual representation.
     *
     * @private
     * @returns {string} A formatted string describing the included duration components.
     */
    _toString(): string;
    /**
     * Converts the internal duration equivalent into a JSON-compatible representation.
     *
     * @private
     * @returns {any} A JSON object containing duration components and optional fractional information.
     */
    _toJson(): any;
}