@Field
    public void setHttpRequestHeaders(List<String> headers) {
        this.httpRequestHeaders.clear();
        this.httpRequestHeaders.addAll(headers);

        httpFetcherConfig.setHttpRequestHeaders(new HttpHeaders());
        if (headers != null) {
            Map<String, Collection<String>> allParsedHeaders = new HashMap<>();
            for (String header : headers) {
                Map<String, Collection<String>> parsedHeaders = parseHeaders(header);
                allParsedHeaders.putAll(parsedHeaders);
                // httpFetcherConfig.getHttpRequestHeaders().getMap() doesn't work:
                // "The map does not support put or putAll, nor do its entries support setValue."
            }
            httpFetcherConfig.getHttpRequestHeaders().setMap(allParsedHeaders);
        }
    }
Which http request headers should we send in the http fetch requests.

@param headers The headers to add to the HTTP GET requests.
tika-pipes/tika-fetchers/tika-fetcher-http/src/main/java/org/apache/tika/pipes/fetcher/http/HttpFetcher.java