/**
 * Compress class names based on `classNameCompressionMap`.
 * The compressed class name has a format of `_aaaa_a`, which is expected by `ac`.
 * `aaaa` is the atomic group and `a` is the compressed name.
 */
export declare const compressClassNamesForRuntime: (classNames: string[], classNameCompressionMap?: {
    [index: string]: string;
} | undefined) => string[];