import { ConversionOptions, PageProperties } from '../interfaces/converter.types';
import { PathLikeOrReadStream } from '../../common';
/**
 * Utility class for handling common tasks related to conversion.
 */
export declare class ConverterUtils {
    /**
     * Validates if a value is a valid unit string (e.g., "72pt", "1in", "25.4mm").
     *
     * @param {string} value - The value to validate.
     * @returns {boolean} True if the value matches the expected unit format.
     */
    private static isValidUnitString;
    /**
     * Adds page properties to the FormData object based on the provided PageProperties.
     *
     * @param {FormData} data - The FormData object to which page properties will be added.
     * @param {PageProperties} pageProperties - The page properties to be added to the FormData.
     */
    static addPageProperties(data: FormData, pageProperties: PageProperties): void;
    /**
     * Adds files to the FormData object with a custom field name.
     *
     * @param {PathLikeOrReadStream[]} files - An array of files to be added to the FormData.
     * @param {FormData} data - The FormData object to which files will be added.
     * @param {string} fieldName - The field name to use when appending files (e.g., 'files', 'embeds').
     * @returns {Promise<void>} A Promise that resolves once the files have been added.
     */
    static addFilesWithFieldName(files: PathLikeOrReadStream[], data: FormData, fieldName: string): Promise<void>;
    /**
     * Customizes the FormData object based on the provided conversion options.
     *
     * @param {FormData} data - The FormData object to be customized.
     * @param {ConversionOptions} options - The conversion options to apply to the FormData.
     * @returns {Promise<void>} A Promise that resolves once the customization is complete.
     */
    static customize(data: FormData, options: ConversionOptions): Promise<void>;
}