/**
 * Generate a compression map, which is used by @compiled/babel-plugin to compress class names.
 * The compression map looks like { 'aaaabbbb': 'a', 'bbbbcccc': 'b' }
 *
 * @param stylesheet css content i.e. `.aaaabbbb{font-size: 10px}`
 * @param oldClassNameCompressionMap the previous compression map, which ensures the compression is deterministic.
 * @returns newClassNameCompressionMap
 */
export declare const generateCompressionMap: (css: string, opts?: {
    oldClassNameCompressionMap?: {
        [index: string]: string;
    } | undefined;
    prefix?: string | undefined;
} | undefined) => {
    [index: string]: string;
} | undefined;