import { AxiosInstance } from 'axios';
import 'core-js/proposals/array-buffer-base64';
export declare class ValueSetResolver {
    protected apiKey: string;
    instance: AxiosInstance;
    constructor(apiKey: string);
    private authHeaderValue;
    getExpansionForValuesetUrls(urls: string[]): Promise<[fhir4.ValueSet[], string[]]>;
    findMissingValuesets(missingVSURLs: string[], expansions: fhir4.ValueSet[]): string[];
}