/**
 * Utility function for merging headers.
 *
 * @packageDocumentation
 * @internal
 */
/// <reference types="node" resolution-mode="require"/>
/**
 * @internal
 */
export declare function mergeHeaders(base: Headers, extra: Headers | Record<string, string> | undefined): Headers;
//# sourceMappingURL=mergeHeaders.d.ts.map