import { Document } from "../document.js";
import { Serializable } from "../load/serializable.js";
/**
 * Abstract base class for document transformation systems.
 *
 * A document transformation system takes an array of Documents and returns an
 * array of transformed Documents. These arrays do not necessarily have to have
 * the same length.
 *
 * One example of this is a text splitter that splits a large document into
 * many smaller documents.
 */
export declare abstract class BaseDocumentTransformer extends Serializable {
    lc_namespace: string[];
    /**
     * Transform a list of documents.
     * @param documents A sequence of documents to be transformed.
     * @returns A list of transformed documents.
     */
    abstract transformDocuments(documents: Document[]): Promise<Document[]>;
}