/**
 * @packageDocumentation
 *
 * A transformer that combines multiple transformers.
 */
import { Transformer } from './Transformer.cjs';
/**
 * A transformer that combines multiple transformers.
 */
export declare class GroupTransformer extends Transformer {
    private readonly transformers;
    /**
     * An id of the transformer.
     *
     * @returns `group`.
     */
    get id(): string;
    /**
     * Transformers to combine.
     *
     * @param transformers - The transformers to combine.
     */
    constructor(transformers: Transformer[]);
    /**
     * Determines if the value can be transformed by any of the transformers.
     *
     * @param value - The value to check.
     * @param key - The key of the value to check.
     * @returns A boolean indicating if the value can be transformed.
     */
    canTransform(value: unknown, key: string): boolean;
    /**
     * Gets the transformer with the given id.
     *
     * @param transformerId - The id of the transformer to get.
     * @returns The transformer with the given id.
     */
    getTransformer(transformerId: string): Transformer;
    /**
     * Transforms the value using the first transformer that can transform it.
     *
     * @param value - The value to transform.
     * @param key - The key of the value to transform.
     * @returns The transformed value.
     */
    transformValue(value: unknown, key: string): unknown;
    /**
     * Gets the id of the transformer that can transform the given value.
     *
     * @param value - The value to get the transformer id for.
     * @param key - The key of the value to get the transformer id for.
     * @returns The id of the transformer that can transform the given value.
     */
    protected getTransformerId(value: unknown, key: string): null | string;
    /**
     * This transformer does not support restoring values.
     *
     * @throws
     */
    protected restoreValue(): never;
    /**
     * Gets the first transformer that can transform the given value.
     *
     * @param value - The value to get the first transformer for.
     * @param key - The key of the value to get the first transformer for.
     * @returns The first transformer that can transform the given value.
     */
    private getFirstTransformerThatCanTransform;
}