/**
 * MIME class.
 */
export declare class Mime {
    /**
     * Custom MIME types.
     */
    custom: Record<string, string>;
    _reverseCustom: Record<string, string> | undefined;
    /**
     * Detect file extensions from `Accept` header value.
     */
    detect(accepts: string): string[];
    /**
     * Get MIME type for file extension.
     */
    extType(ext: string): string | null;
}