import { PathLikeOrReadStream } from '../../common';
import { ConversionOptions, MergeOptions } from '../interfaces/pdf-engines.types';
/**
 * Utility class for handling common tasks related to PDF engine operations.
 */
export declare class PDFEnginesUtils {
    /**
     * Adds PDF files to the FormData object.
     *
     * @param {PathLikeOrReadStream[]} files - An array of PDF files to be added to the FormData.
     * @param {FormData} data - The FormData object to which PDF files will be added.
     * @throws {Error} Throws an error if the file extension is not supported.
     */
    static addFiles(files: PathLikeOrReadStream[], data: FormData): Promise<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 | MergeOptions} options - The options to apply to the FormData.
     * @returns {Promise<void>} A Promise that resolves once the customization is complete.
     */
    static customize(data: FormData, options: ConversionOptions | MergeOptions): Promise<void>;
}